Steam Cured Self-Consolidating Concrete and the …...ii Steam Cured Self-Consolidating Concrete and the Effects of Limestone Filler Mohammad A. Aqel Doctor of Philosophy Civil Engineering

Steam Cured Self-Consolidating Concrete and the Effects of Limestone Filler

by

Mohammad A. Aqel M.Sc., PMP, LEED AP BD+C, EIT

A thesis submitted in conformity with the requirements for the degree of

Doctor of Philosophy Department of Civil Engineering

University of Toronto

© Copyright by Mohammad A. Aqel (2016)

ii

Steam Cured Self-Consolidating Concrete and the Effects of

Limestone Filler

Mohammad A. Aqel

Doctor of Philosophy

Civil Engineering Department

University of Toronto

2016

Abstract

The purpose of this thesis is to determine the effect and the mechanisms associated with

replacing 15% of the cement by limestone filler on the mechanical properties and durability

performance of self-consolidating concrete designed and cured for precast/prestressed

applications. This study investigates the role of limestone filler on the hydration kinetics,

mechanical properties (12 hours to 300 days), microstructural and durability performance

(rapid chloride permeability, linear shrinkage, sulfate resistance, freeze-thaw resistance

and salt scaling resistance) of various self-consolidating concrete mix designs containing

5% silica fume and steam cured at a maximum holding temperature of 55°C. This research

also examines the resistance to delayed ettringite formation when the concrete is steam

cured at 70°C and 82°C and its secondary consequences on the freeze-thaw resistance. The

effect of several experimental variables related to the concrete mix design and also the

curing conditions are examined, namely: limestone filler fineness, limestone filler content,

cement type, steam curing duration and steam curing temperature.

In general, the results reveal that self-consolidating concrete containing 15% limestone

filler, steam cured at 55°C, 70°C and 82°C, exhibited similar or superior mechanical and

transport properties as well as long term durability performance compared to similar

concrete without limestone filler. When the concrete is steam cured at 55°C, the chemical

reactivity of limestone filler has an important role in enhancing the mechanical properties

at 16 hours (compared to the concrete without limestone filler) and compensating for the

dilution effect at 28 days. Although, at 300 days, the expansion of all concrete mixes are

iii

below 0.05%, the corresponding freeze-thaw durability factors vary widely and are

controlled by the steam curing temperature and the chemical composition of the cement.

Overall, the material properties indicate that the use of 15% limestone filler as cement

replacement is a viable option for the precast/prestressed concrete applications, and in

addition, would also have economic and environmental benefits.

iv

Acknowledgements

I would like to take this opportunity to express my special appreciation and thanks to my

supervisor Prof. Daman K. Panesar for her continued support, guidance and

encouragement. I would like to acknowledge the support and guidance provided by my

PhD examination committee members Prof. Doug Hooton, Prof. Karl Peterson and Prof.

Kim Pressnail. I sincerely appreciate Prof. Kamal Khayat for his support as the external

examiner of my thesis.

I would like to thank my parents Dr. Abdullah Aqel and Eman Othman and my brothers

and sister for their continuous support and prayers. Although, I was away from them for

more than four years, their support was felt as they were living with me.

Finally, a special thanks to my family. Words cannot express how grateful I am to my wife

Luma and my sons Yousef and Zain for their support throughout my PhD study. I love you

all.

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List of Acronyms

AASHTO American Association of State Highway and Transportation Officials

AEA Air-entraining Admixture

ACI American Concrete Institute

AFm Alumina, Ferric Oxide, Mono-sulfate

ASTM American Society for Testing and Materials

BF Brucite Filler

COV Coefficient of Variation

CPCI Canadian Precast/Prestressed Concrete Institute

CSA Canadian Standard Association

CSH Calcium Silicate Hydrate

DEF Delayed Ettringite Formation

DOT Department of Transportation

DTA Differential Thermal Analysis

GU General Use (CSA A3000)

GUL General Use with Limestone (CSA A3000)

HE High Early Strength

HRWR High-range Water Reducer

HS High Sulfate Resistance

ITZ Interfacial Transition Zone

LF Limestone Filler

LOI Loss on Ignition

MK Metakaolin

MIP Mercury Intrusion Porosimetry

MTO Ministry of Transportation - Ontario

OPSS Ontario Provincial Standard Specification

PCI Precast/Prestressed Concrete Institute

PLC Portland-Limestone Cement

RCPT Rapid Chloride Permeability Test

RH Relative Humidity

S/A Sand-to-total Aggregate Ratio

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SCC Self-Consolidating Concrete

SCM Supplementary Cementitious Materials

SEM Scanning Electron Microscopy

SF Silica Fume

TG Thermal Gravimetric Analysis

UPV Ultrasonic Pulse Velocity

VSI Visual Stability Index

W/C Water-to-cement Ratio

wt% Percentage by Weight

vii

Table of Contents

Chapter 1 - Thesis Overview .............................................................................................. 1

1.1. Introduction .......................................................................................................... 1

1.2. Research Objectives ............................................................................................. 3

1.3. Research Outline .................................................................................................. 4

1.4. Background .......................................................................................................... 7

1.4.1. Limestone as a Cement Replacement ........................................................... 7

1.4.2. Energy Saving by Using Limestone ............................................................. 8

1.4.3. Economic Evaluation of Using Self-Consolidating Concrete in

Precast/Prestressed Applications ................................................................................ 9

1.4.4. Effect of Steam Curing Temperature .......................................................... 10

1.5. References .......................................................................................................... 14

Chapter 2 - Physical and Chemical Effects of Limestone Filler on Steam Cured Cement

Paste, Mortar and Concrete ............................................................................................... 23

2.1. Introduction ........................................................................................................ 23

2.2. Experimental Program........................................................................................ 26

2.2.1. Materials ..................................................................................................... 26

2.2.2. Mix Designs ................................................................................................ 28

2.2.3. Curing Regime ............................................................................................ 29

2.2.4. Test Methods ............................................................................................... 30

2.3. Results and Discussion ....................................................................................... 32

2.3.1. Heat of Hydration ....................................................................................... 32

2.3.2. Thermal Analysis ........................................................................................ 34

2.3.3. X-Ray Diffraction ....................................................................................... 36

2.3.4. Mercury Intrusion Porosimetry ................................................................... 37

2.3.5. Compressive Strength of Mortar and Concrete .......................................... 38

viii

2.3.6. Transport Properties .................................................................................... 40

2.3.7. Physical and Chemical Effects of Limestone Filler .................................... 43

2.4. Conclusions ........................................................................................................ 46

2.5. References .......................................................................................................... 47

Chapter 3 - Hydration Kinetics and Compressive Strength of Steam-Cured Cement Pastes

and Mortars Containing Limestone Filler ......................................................................... 51

3.1. Introduction ........................................................................................................ 52


3.2.1. Materials and Mix Design ........................................................................... 54

3.2.2. Curing Regime ............................................................................................ 55

3.2.3. Test Methods ............................................................................................... 57


3.3.1. Influence of Limestone Filler Size and Content ......................................... 58

3.3.2. Influence of Cement Fineness ..................................................................... 74

3.3.3. Influence of Steam Curing Duration ........................................................... 75

3.3.4. Influence of Reacted Limestone Filler ........................................................ 75

3.3.5. Statistical Analysis ...................................................................................... 77

3.4. Conclusions ........................................................................................................ 78

3.5. Acknowledgments .............................................................................................. 79

3.6. References .......................................................................................................... 79

Chapter 4 - Effect of Cement and Limestone Particle Size on the Durability of Steam Cured

Self-Consolidating Concrete ............................................................................................. 83

4.1. Introduction ........................................................................................................ 84


4.2.1. Materials ..................................................................................................... 86

4.2.2. Mix Design.................................................................................................. 86

4.2.3. Mixing and Curing ...................................................................................... 88

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4.2.4. Test Methods ............................................................................................... 90


4.3.1. Normal Consistency and Initial Setting Time ............................................. 92

4.3.2. Heat of Hydration ....................................................................................... 93

4.3.3. Thermal Analysis ........................................................................................ 94

4.3.4. Mortar Compressive Strength ..................................................................... 97

4.3.5. Plastic Properties of Concrete ..................................................................... 99

4.3.6. Hardened Properties of Concrete .............................................................. 100

4.3.7. Transport Properties of Concrete .............................................................. 105

4.3.8. Durability Performance of Concrete ......................................................... 106

4.4. Statistical Analysis ........................................................................................... 110

4.5. Conclusions ...................................................................................................... 112

4.6. Acknowledgments ............................................................................................ 113

4.7. References ........................................................................................................ 113

Chapter 5 - Delayed Ettringite Formation in Self-Consolidating Concrete Containing

Limestone Filler .............................................................................................................. 117

5.1. Introduction ...................................................................................................... 118

5.2. Experimental Program...................................................................................... 119

5.2.1. Materials ................................................................................................... 119

5.2.2. Mix Design................................................................................................ 121

5.2.3. Curing Regime .......................................................................................... 122

5.2.4. Testing Methods........................................................................................ 123

5.3. Results and Discussion ..................................................................................... 124

5.3.1. Fresh Properties ........................................................................................ 124

5.3.2. Air Void Analysis of Hardened Concrete ................................................. 125

5.3.3. Compressive Strength ............................................................................... 125

5.3.4. Ultrasonic Pulse Velocity ......................................................................... 130

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5.3.5. Rapid Chloride Permeability..................................................................... 132

5.3.6. Concrete Expansion .................................................................................. 134

5.3.7. Scanning Electron Microscopy ................................................................. 137

5.3.8. Freeze-Thaw Resistance ........................................................................... 148

5.4. Conclusions ...................................................................................................... 151

5.5. Acknowledgments ............................................................................................ 153

5.6. References ........................................................................................................ 153

Chapter 6 - Key Findings, Contributions and Recommendations .................................. 158

6.1. Key Findings and Contributions ...................................................................... 158

6.2. Recommendations ............................................................................................ 160

Appendix A - Testing Data ............................................................................................. 162

A.1. Particle Size Distribution of Sand and Aggregate .................................................. 162

A.2. Materials Properties ................................................................................................ 163

A.3. Mixing and Batching of Concrete ........................................................................... 164

A.4. Mortar and Concrete Mix Designs .......................................................................... 166

A.5. Chapter 2 Results .................................................................................................... 169

A.6 Chapter 3 Results ..................................................................................................... 170

A.7 Chapter 4 and 5 Results ........................................................................................... 178

A.7.1 Cement Paste and Mortar Results ......................................................................... 178

A.7.2 Fresh Properties of Concrete ................................................................................. 180

A.7.3 Mechanical Properties of Concrete ....................................................................... 181

A.7.4 Transport Properties of Concrete .......................................................................... 195

A.7.5 Durability Performance of Concrete/Mortar ......................................................... 197

A.7.5.1 Concrete Expansion ........................................................................................... 202

A.7.5.1.1 Effect of Limestone Filler ............................................................................... 202

A.7.5.1.2 Effect of Intergrinding Versus Blending of Limestone .................................. 205

xi

A.7.6 Scanning Electron Microscopy ............................................................................. 216

Appendix B Publication Plan ......................................................................................... 229

1

Chapter 1 - Thesis Overview

1.1. Introduction

Concrete is one of the most consumed materials on earth. In Canada, it is estimated that

28.1 million tonnes of concrete are produced annually [1]. This corresponds to

approximately one cubic meter of concrete consumed per capita. The main binding material

in concrete is cement which holds 10 to 15% of concrete volume. In 2004, global cement

production was estimated to be 298 million tonnes and was responsible for 3.8% of the

global CO2 emissions [2]. In 2014, the cement production increased to 4.2 billion tonnes

which was responsible for 9% of global CO2 emissions [3,4]. This is due to the fact that

one tonne of cement produces approximately 900 kg of CO2 [5]. Moreover, the global

demand for cement is increasing and actions have been taken to research other approaches

that could reduce cement consumption. Governments have begun to place a carbon tax on

the production of CO2; such laws were implemented in Canada (in the provinces of Alberta,

British Columbia and Quebec) and in many U.S. states [6]. Currently, the carbon tax varies

from $3.5/tonne of CO2 in Quebec to $30/tonne of CO2 in British Columbia. In 2015,

Ontario started developing its cap and trade program, which will include a carbon tax

system.

The negative environmental impact of cement can be reduced by improving manufacturing

techniques, using alternative fuels or clinker substitution [7]. It has been reported that

improved manufacturing techniques or the use of alternative fuels has less potential for

reduction in CO2 emission compared to cement substitution [7,8]. This is because the main

source of CO2 emission in cement production is the calcination of raw materials which

produces approximately 50 to 55% of the CO2 emission while burning fuels produces 35%

and transportation produces 10% [8]. Cement substitution is reported to be the most

efficient way to achieve a significant reduction of CO2 emission [9]. This substitution can

be done using supplementary cementing materials (SCM) or fillers such as limestone [10,

11]. Fillers are typically finely ground inert materials that are used to reduce the amount of

binding material (i.e., cement). The use of 5% interground limestone as cement

replacement by weight was accepted by the Canadian Standards Association (CSA) A5 in

1983 [12]. In 2009, CSA A23.1 introduced a new type of cement known as Portland

2

limestone cement (PLC), which contains up to 15% of interground limestone by weight

[13]. Limestone can be added either by intergrinding or blending. However, the current

CSA A23.1 allows the use of interground limestone only. In the intergrinding process,

limestone (as coarse particles) is added to the cement clinker and is ground together to

produce the cement. For the blending process, limestone as a powder is blended with the

cement.

Limestone can also be utilized to reduce the cost of concrete [14]. The potential for cost

reduction can be particularly visible in concrete made with high cement contents such as

self-consolidating concrete (SCC), which typically has a higher cost compared to

traditional concrete. The relatively higher cost of SCC is partly due to the necessity for

various chemical admixtures, and more stringent formwork requirements [15,16]. SCC is

also typically made with lower water-to-cement ratios (0.32 to 0.36) compared to

traditional concrete. This increases the portion of cement that remains unhydrated, which

acts as an expensive filler [17].

Utilizing SCC in the construction industry has been proven to have several benefits

including: i) decreasing the labour needs and casting time, ii) eliminating the need for

surface finishing and iii) improving the work environment and safety by reducing noise

exposure and congestion at the casting location [18,19]. Replacing cement with a relatively

less expensive material such as limestone has the potential to be an economical and

environmentally viable option for precast/prestressed SCC if it can achieve the desired

strength gain and durability performance [20,21]. Owing to the importance of early age

strength gain in precast/prestressed applications (demolding or stressing strength: 28 to 35

MPa in the first 16 to 18 hours) it is critical to understand the role of limestone to minimize

any negative impact on the mechanical properties or durability performance. The potential

for negative impact is caused by replacing reactive cementitious materials with less

reactive material (i.e., limestone) and is referred to as the dilution effect [17,22].

The influence of limestone on concrete properties, when cured at an ambient temperature

(i.e., 23°C), has been the focus of many research studies [12,23,24]. However, the results

of the workability, hardened properties and durability performance often vary [12,23]. This

variation in the results could be due in part to the variation in limestone chemical

composition and fineness, and whether the limestone was used as a replacement of cement,

3

sand or cement paste. Inadequate dispersion of limestone particles in the mix may also

cause variations in the results [25]. In addition to the variation in the results, there is limited

data available on the influence of limestone when the concrete is steam cured.

In precast/prestressed applications, high early strength is required to maintain efficient

production. This is usually achieved by applying high temperatures in the range of 60°C to

85°C. Higher temperatures increase the hydration rate and the early age strength gain.

However, concrete subjected to steam curing at elevated temperatures in the range of 60°C

to 75°C (depending on factors including cement chemistry) may be vulnerable to

degradation due to delayed ettringite formation (DEF) [26,27]. Therefore, it is critical to

understand the role of LF and how LF interacts with cementing materials under steam

curing conditions, and how this interaction influences the hardened properties and

durability performance of concrete.

1.2. Research Objectives

The purpose of this thesis is to determine the effect and the mechanisms associated with

replacing 15% of the cement by limestone filler on the mechanical properties and durability

performance of self-consolidating concrete designed and cured for precast/prestressed

applications. To achieve this objective, four questions were explored and answered. The

research questions are:

1. What is the contribution of the physical and chemical effects of LF, and how does

each contribution change with age? (In Chapter 2)

2. What is the effect of LF fineness and content on the hydration kinetics and

hydration products in steam cured mortar and cement paste? (In Chapter 3)

3. How does replacing cement with LF influence the early and later age mechanical

properties, transport properties and durability performance of concrete steam cured

at 55°C? (In Chapter 4)

4. What is the effect of LF on concrete expansion at different steam curing

temperatures (55°C, 70°C and 82°C)? Are there any implications of concrete

expansion due to DEF on the freeze-thaw resistance of concrete made with and

without LF? (In Chapter 5)

4

1.3. Research Outline

The research in this thesis was carried out in four stages and is summarized in Figure 1.1.

Table 1.1 presents the key variables in the experimental study for each chapter. Each

chapter explores one of the four research questions presented in the Research Objectives

(Section 1.2). Chapter 6 presents the key findings and contributions of this thesis.

Figure 1.1: Research Layout

Decoupling the Physical and Chemical Effects of LF

(Chapter 2)

Effect of LF Size and Content

(Chapter 3)

SCC Steam Cured at 55°C with/without LF (Chapter 4)

• Fresh Properties

• Mechanical Properties (Density, fc’, E, UPV)

• Transport Properties (RCPT)

• Durability Performance (Sulfate Resistance, Linear

Shrinkage, Freeze-thaw and Salt Scaling)

Effect of LF on SCC Expansion

Due to DEF

Effect of DEF on Freeze-thaw Resistance of SCC

Containing LF

Effect of Steam Curing Temperatures (i.e., 55°C, 70° and 82°C)

(Chapter 5)

Effect of LF on Transport

Properties of SCCMicrostructure Analysis

• Heat of Hydration

• Thermal Analysis• Compressive Strength

• RCPT & Sorptivity

• Heat of Hydration

• Thermal Analysis

• Compressive Strength

5

Table 1.1: Key Differences between Experimental Work Carried out in Each Chapter

Chapter

Mix Design Parameters Steam

Curing

Temp.

Experimental Variable

System w/c Cement

Type

Silica

Fume Primary Secondary

2

Paste

Mortar

Concrete

0.34 HE 0% 55°C

Effect of LF

(physical vs.

chemical

effect)

---

3 Paste

Mortar 0.37

GU

HE 0% 55°C

LF content

LF size

Cement fineness

Steam curing

duration

4

Paste

Mortar

Concrete

0.34 GU

HE 5% 55°C

LF content

LF size

Cement

fineness

Steam curing

duration

Moist curing

duration

5 Concrete 0.34

GU

HE

GUL

HS

5%

55°C

70°C

82°C

Steam curing

temperature

LF content

LF size

Cement type

Intergrading vs.

blending of

limestone

Moist curing

duration

Chapter 2 is focused on examining the physical and chemical effects of LF on steam cured

cement paste, mortar and concrete. The physical and the chemical effects of LF when used

as a cement replacement were decoupled. This was done using a brucite filler [Mg(OH)2

(BF)] with similar physical characteristics compared to LF. Identifying the relative

contribution of the physical and chemical effects is an important step in understanding how

LF interacts with cementing materials under steam curing conditions. Paste, mortar and

concrete specimens were steam cured at 55°C. The total duration of the steam curing

regime was 16 hours. The heat of hydration, thermal analysis, compressive strength,

mercury intrusion porosimetry and transport properties were evaluated at 16 hours and 28

days.

Chapter 3 is focused on the hydration kinetics and compressive strength of steam-cured

cement pastes and mortars containing LF. The experimental variables in this chapter were

cement fineness, LF content, LF fineness and steam curing duration. Mortar and paste

specimens were steam cured at 55°C. The total duration of the steam curing regime was 12

and 16 hours. Hydration kinetics was studied by examining the heat of hydration and

thermal analysis. The heat of hydration was measured using Isothermal Calorimetry.

Calcium hydroxide (Ca(OH)2) content, calcium carbonate (CaCO3) content and degree of

6

hydration were measured using Thermal Gravimetric Analysis and Differential Thermal

Analysis (TG/DTA). The compressive strength of mortars was evaluated at 12 and 16 hours

and at 3, 7 and 28 days.

In Chapter 4, the findings obtained from Chapters 2 and 3 are utilized to design SCC mixes

that satisfy the early age strength requirements for precast/prestressed concrete applications

in Ontario, Canada (i.e., a minimum of 44 MPa at 16 hours). The influence of cement and

LF particle size on the hardened properties and durability performance of steam cured SCC

was investigated. In addition, the interplay between cement fineness and LF particle size

was evaluated. CSA Type general use (GU) and high early strength (HE) cements were

used with 5% silica fume. LF with two nominal particle sizes of 17µm and 3µm, which

correspond to Blaine finenesses of 475 and 1125 m2/kg, respectively, were used. In

addition to the plastic concrete properties, hardened properties including compressive

strength, elastic modulus, ultrasonic pulse velocity and density were measured at 12 and

16 hours, and at 3, 7 and 28 days. Durability performance including rapid chloride

permeability testing (RCPT), sulfate resistance, linear shrinkage, salt scaling resistance and

freeze-thaw resistance were evaluated.

Chapter 5 is focused on examining the influence of LF on the long-term durability

performance of concrete steam cured at different temperatures. This is important to identify

any negative impact of LF and steam curing temperature on the long-term durability

performance of concrete. The influence of steam curing temperature, cement type, cement

fineness on the expansion of concrete made with and without LF was investigated. Four

types of cement, namely CSA type GU, HE, general use limestone (GUL) and high sulfate

resistance (HS), were used. LF with two nominal particle sizes of 17µm and 3µm were

used to replace 15% of cement. All concrete mixes had 5% silica fume and w/c of 0.34.

The concrete samples were steam cured at a maximum temperature of 55°C, 70°C and

82°C. The total duration of the steam curing regime was 16 hours. The hardened properties

were evaluated using compressive strength and ultrasonic pulse velocity at 16 hours, and

at 3, 7, 28 and 300 days. The transport properties were evaluated using the rapid chloride

permeability test (RCPT) at 28 and 300 days. The durability performance of concrete was

assessed by monitoring concrete expansion and freeze-thaw resistance. Concrete expansion

in water was measured for 300 days followed by freeze-thaw testing for 300 cycles.

7

1.4. Background

1.4.1. Limestone as a Cement Replacement

When replacing cement, limestone influences the behaviour of cement through physical

and chemical effects. The physical effect is caused by (i) modification of particle size

distribution, (ii) dilution and (iii) heterogeneous nucleation. Modification of particle size

distribution and heterogeneous nucleation can improve the properties of concrete whereas

dilution has adverse effects. The chemical effect of limestone is the chemical reaction

between limestone with monosulfate and calcium aluminate hydrates in the hydrated

cement system. The influence of each effect is discussed in the following sections.

1.4.1.1. Physical Effect of Limestone

Modification of Particle Size Distribution

Limestone has a relatively low hardness compared to cement clinker, therefore, when

interground, it produces a wider particle size distribution compared to cement [23,28].

Limestone particles fill the voids between coarser particles (i.e., cement and sand particles),

which can increase the concrete density and decrease the volume of pores in concrete

[22,29]. In fresh concrete, limestone can replace some of the water in the voids. The water

replaced by limestone provides an additional reduction in the internal friction, which causes

an improve in the workability of concrete [24,30]. However, this improvement in the

workability has shown to be insignificant due to the higher water adsorption when

limestone fineness increases [31]. Limestone can also reduce the bleeding of concrete at

replacement levels greater than 5% [32]. At replacement levels of less than 5%, the

bleeding is thought to only be influenced by the surface area of the cement [32].

Dilution

Dilution occurs as a result of replacing reactive material such as cement by an inert or

relatively less reactive material such as limestone [33]. A reduction in the cement content

decreases the volume of hydration products, and adversely affects the compressive

strength, porosity and permeability of concrete. When the content of interground limestone

is greater than 5% in the cement, the effect of dilution masks the other limestone effects

(i.e., modification of particle size distribution, heterogeneous nucleation and chemical

reaction). However, the dilution effect is minimized when limestone content is less than

5% [34]. Although dilution negatively impacts the properties of concrete at all ages, it is

8

mainly observed at later ages (i.e., after 3 days) [35]. This is due to the heterogeneous

nucleation effect of limestone that compensates for the dilution effect at early age (i.e.,

before 3 days) [35].

Heterogeneous Nucleation

Limestone particles act as nucleation sites for the precipitation of the hydration products,

which mainly depends on the fineness of limestone [36,37,38]. The nucleation sites

provided by limestone reduce the energy barrier and allow the hydration products to

precipitate faster from the pore solution. This accelerates the cement hydration process and

early age strength gain [37]. In addition, the surface area of limestone will accommodate

precipitation of some of the hydration products, which reduces the thickness of the

hydration products coating unhydrated cement particles [39]. This allows the inner part of

unhydrated cement particles to hydrate sooner and thus accelerate the hydration process.

1.4.1.2. Chemical Effect of Limestone

Research studies in the past 20 years have proven that limestone is not an inert material but

rather partially reactive [12,24,40]. In the hydrated cement system, limestone chemically

reacts with monosulfate ((CaO)3(Al2O3)·CaSO4·12H2O) and calcium aluminate hydrate

((CaO)3(Al2O3)·6H2O) in the presence of water to form calcium monocarboaluminate

(3CaO·Al2O3·CaCO3·11H2O). The chemical reactions of limestone are presented in

Equations 1.1 and 1.2 [41,42]. The fineness of limestone influences these reactions; the

higher the fineness of limestone, the more limestone is consumed in these reactions [12].

3(CaO)3(Al2O3)·CaSO4·12H2O + 2CaCO3 + 18H2O → 2(CaO)3(Al2O3)·CaCO3·11H2O +

(CaO)3(Al2O3)·3CaSO4·32H2O Eq.1.1

(CaO)3(Al2O3)·6H2O + CaCO3 + 5H2O → (CaO)3(Al2O3)·CaCO3·11H2O Eq.1.2

1.4.2. Energy Saving by Using Limestone

Cement production is considered to be one of the highest energy demanding industries

compared to other mineral-processing industries [43]. Energy consumption is responsible

for approximately 40% of cement production costs [44]. This is because the raw materials

are heated to approximately 1450°C to produce cement clinker [5,45]. The production

process can be classified into two different processes, namely dry and wet processes. The

two processes are similar except that in the wet process the raw materials are ground with

9

water before burning in the kiln [46]. However, in most modern cement manufacturing

plants, the dry process is used. The wet process has greater energy requirements and lower

efficiency compared to the dry process [47]. The energy required for heating raw materials

in a modern dry process cement plant is typically 990 kWh per tonne of cement. This

energy is usually produced by burning coal, oil fuel or natural gas [43]. Once cement

clinker is produced, the clinker is ground using electrical-powered mills to achieve the

required fineness. The grinding process consumes approximately 120 kWh of electricity

per tonne of cement. Therefore, the total amount of fuel or coal required for heating and

grinding is 111 kg of fuel oil or 233 kg of coal to produce one tonne of cement [35].

Replacing clinker with limestone reduces the required energy due to the reduction in the

amount of clinker. However, because limestone is softer than clinker, cement interground

with limestone will have coarser cement particles compared to cement without limestone

[48]. Therefore, it requires more grinding to achieve the same strength of cement without

limestone. When cement contains 5% of interground limestone, the energy required for

extra grinding is estimated to be 2 kWh per tonne of cement. However, this additional

energy is offset by a reduction of 75 kWh per tonne of cement due to the reduction in the

amount of clinker [49].

For a cement plant with a production capacity of 1 million tonnes per year, the total energy

saving is approximately 73 GWh of energy by replacing 5% of cement with limestone.

This energy saving corresponds to approximately 7% of the annual energy usage. The

saving is expected to be higher with an increase in limestone content; however, the

relationship is not linear. Other estimates have shown an annual saving of $420,000USD

per 1% replacement of limestone for cement plant with a production capacity of 1 million

tonnes per year [50].

1.4.3. Economic Evaluation of Using Self-Consolidating Concrete in Precast/Prestressed Applications

The principal disadvantage of SCC is the higher cost compared to traditional concrete due

to the higher cement content and the use of various chemical admixtures [51]. In addition,

SCC requires a more robust formwork system and thus can be costly [51]. However, the

higher costs of materials and formwork when using SCC could be compensated for by the

decrease in construction time as well as a decrease in repair and patching costs due to

10

improved surface finishing. SCC can also reduce labour costs and can compensate for a

lack of skilled workers [52]. Furthermore, SCC eliminates the use of vibrators, which

minimizes the noise and congestion at the casting location. A cost analysis of

precast/prestressed T-girders used for the main girders of the Higashi-Oozu Viaduct in

Japan was conducted [53]. The cost analysis showed that SCC increased the material cost

by approximately 5% compared to traditional concrete. However, this cost increase was

offset by a 33% reduction in labour cost, which yielded a 7% saving in the total cost of the

project compared to traditional concrete. Another cost analysis showed an average

reduction of 44% in man-hours per precast element [54]. In terms of production efficiency,

implementing SCC in precast/prestressed applications can yield up to a 50% reduction in

casting time compared to traditional concrete [55]. Furthermore, SCC can reduce up to

10% of the cost when used for precast elements with a high surface-to-volume ratio (i.e.,

slabs) due to the elimination of screeding [54].

1.4.4. Effect of Steam Curing Temperature

Although steam curing increases the early age strength of concrete, the 28-day compressive

strength could be reduced compared to moist cured concrete [56,57]. A maximum steam

curing temperature of 82°C was suggested to prevent any significant decrease in the 28-

day strength compared to concrete cured at maximum temperatures of 43°C and 63°C [58].

More recent studies suggested using lower steam curing temperatures (50°C to 70°C) to

prevent any long-term strength or durability issues caused by degradation due to delayed

ettringite formation (DEF) [26,27,59].

1.4.4.1. Delayed Ettringite Formation

DEF is a type of internal sulfate attack, and is one of the main concerns in

precast/prestressed applications largely owing to the commonly used elevated curing

temperatures.

Mechanism of Delayed Ettringite Formation

For DEF to occur, three conditions need to exist: exposure to elevated temperature at early

age, sufficient sulfate content in the cement and a supply of moisture [26,60,61]. A

thermodynamic stability study conducted on ettringite showed that ettringite is not stable

at temperatures greater than 60°C because it transforms to monosulfate and gypsum, as

presented in Figure 1.2 [62]. However, in context with cement-based systems and at

11

temperatures greater than 60°C, ettringite can exist if enough sulfate is available in the

system [26]. The ability of calcium silicate hydrate (CSH) to adsorb sulfate ions is

increased with the increase in temperature [63]. This adsorption process is further increased

as the pH increases, which is mainly linked to the alkali content of the cement [26,64].

When the temperature decreases, the sulfate ions are slowly released. Monosulfate in the

presence of sulfate ions and moisture transform to ettringite. A portion of this ettringite

known as DEF forms in the paste, which causes the paste to expand and crack [26].

Ettringite has been reported to exist in cracks in mortar and concrete deteriorated by DEF.

However, the ettringite forming in cracks is not the cause of DEF damage. This formation

of ettringite in the cracks is a recrystallization of ettringite commonly referred to as

secondary ettringite, which occurs after the cracks have been created [65]. In the presence

of cracks, the volume of water ingress into the concrete increases, which promotes the

dissolution process of small ettringite crystals and recrystallization in existing spaces

including air voids and cracks [65].

Factors Influencing Delayed Ettringite Formation

The main factors that influence the risk of DEF are (i) exposure to elevated temperatures

(greater than 70°C) at early age, (ii) high sulfate content (greater than 4% by weight of

cement) and (iii) exposure to a wet environment [26,65,66]. Exposing the concrete at early

age to temperatures greater than 70°C increases the risk of DEF [26]. This is due to the

increase in sulfate ions adsorbed by the CSH, which are later released over time after

concrete is cooled and hardened [26,27]. The expansion of concrete due to DEF is greatly

influenced by the presence of water. Water is an essential part of the reaction to form

ettringite since one molecule of ettringite contains 32 molecules of water. The water also

plays an important role in the leaching of alkali from the concrete [67]. The reduction in

alkalinity due to leaching or alkali silica reaction increases the risk of DEF [67]. It has been

reported that for concrete, a minimum of 92% relative humidity is required for DEF

expansion to occur [68,69].

The alkali content in the cement also plays an important role in the damage due to DEF. In

concrete exposed to elevated temperatures greater than 70°C, the increase in pH of the pore

solution due to the high alkali content in cement increases the amount of sulfate ions

adsorbed to CSH. The increase in alkali content in the cement increases the solubility of

12

ettringite [67]. This increase in the solubility of ettringite is greater with the higher

temperatures.

Cements with higher fineness have been reported to have increased risk to DEF [70,71].

The increased risk to DEF in finer cement could be partly due to the higher gypsum content

compared to coarser cement, which is required to control the rapid hydration of finer

cement.

The use of some pozzolanic materials or SCM such as fly ash, slag and metakaolin at

replacement levels of 15% to 35% of cement can reduce the vulnerability to DEF [59,72].

Silica fume (SF) was reported to be less effective in reducing the risk due to DEF at

replacement levels less than 15% [72]. This was attributed to the lower alumina content in

SF [72]. Entrained air voids can provide some physical protection to the concrete by

providing relief valves for ettringite growth in hardened concrete [73]. However, the

entrained air voids do not prevent DEF. They allow some of the ettringite to form in the air

voids as a secondary ettringite rather than forming as DEF in the confined paste pore

structure [74].

Figure 1.2: Thermodynamic Stability of AFt and AFm Phases in Hydrated Cement

System [62]

13

Effect of Limestone on Delayed Ettringite Formation

There is limited information in the literature on how limestone influences concrete

expansion due to DEF. A study by Silva et al. (2010) showed that an increase in limestone

content increased the expansion of concrete due to DEF [75]. The authors attributed this

increase to the denser microstructure, observed by petrographic analysis of concrete mixes

made with limestone, which reduced the available space that can accommodate the growth

of ettringite. In contrast, a study by Kurdowski and Duszak (2002) has shown that

limestone and fly ash have a similar efficiency in reducing concrete expansion due to DEF

[76]. Al Shamaa et al. (2016) studied the effect of limestone size on mortar expansion due

to DEF [77]. The results showed that the decrease in limestone size decreased the

expansion of mortar. The authors attributed this reduction to the increase in limestone

reactivity and the production of calcium monocarboaluminate, which reduces the transport

properties of the mortar. However, in this study [77], no control mixture without limestone

was used, and therefore, the effect of limestone on mortar expansion could not be

evaluated.

1.4.4.2. Maximum Holding Temperature Limits in North American Codes

Controlling the curing temperature of concrete is critical to reduce the risk of DEF. In North

America, Canadian Standards Association (CSA A23.4) sets the maximum curing

temperature at 60°C. However, for concrete that will be dry in-service, the maximum

curing temperature is 70°C. The Ontario Provincial Standard Specifications OPSS909 and

OPSS999F31 set the maximum steam curing temperature to 60°C for non-prestressed

concrete and 70°C for prestressed concrete. Table 1.2 provides examples of codes and their

recommended maximum curing temperatures pertaining to North America [78]. However,

it should be noted that both Washington and New York DOT have specified a limit of

0.75% and 0.70% on alkali content in cement, respectively [79,80]. This may explain the

relatively higher temperature allowed by Washington and New York DOT.

14

Table 1.2: Maximum Allowable Curing Temperatures

Code Maximum Allowable Steam Curing

Temperature (°C)

Canadian Standards Association (CSA A23.4

2009 reaffirmed 2014)

60°C for wet exposure

70°C for dry exposure

Ontario Provincial Standard Specification

(OPSS 909 and OPSS999F31)

70°C for prestressed concrete

60°C for non-prestressed concrete

Michigan DOT (2004) 70°C

Portland Cement Association (2006) 71°C, however 60 is recommended

AASHTO LRFD Bridge Design

Specifications (2004) 71°C

Washington DOT (2002) 80°C

New York State DOT (2002) 85°C

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22

[76] Kurdowski, W., and Duszak, S. (2002). Can Addition of Limestone Eliminate the

Expansion of Mortars due to DEF?. International RILEM TC 186-ISA Workshop on

Internal Sulfate Attack and Delayed Ettringite Formation, 4-6 September, Villars,

Switzerland, pp. 229–235.

[77] Al Shamaa, M., Lavaud, S., Colliat, J., Nahas, G., and Torrenti, J. (2016). Influence

of Limestone Filler and of The Size of the Aggregates on DEF. Université Paris-Est,

France. Retrieved June 2016 from

(http://arxiv.org/ftp/arxiv/papers/1601/1601.03036.pdf).

[78] Hwang, S., Khatib, R., Lee, H., Lee, S., and Khayat, K. (2012). Optimization of

Steam-curing Regime for High-strength, Self-consolidating Concrete for Precast,

Prestressed Concrete Applications. PCI Journal, Summer 2012, pp. 48–62.

[79] New York State Department of Transportation (2014). Standard Specifications

(USC), pp. 330–332.

[80] Washington State Department of Transportation (2016). Standard Specifications for

Road, Bridge, and Municipal Construction. Publication No. M 41-10.

23

Chapter 2 - Physical and Chemical Effects of Limestone Filler on Steam Cured Cement Paste, Mortar and Concrete

Abstract

A method to decouple the physical and chemical effects of limestone filler when used as a

cement replacement is proposed. Limestone filler and a chemically inert material (brucite

Mg(OH)2) with similar physical properties to limestone filler were used. Paste, mortar and

concrete specimens were steam cured at 55°C for 16 hours. The heat of hydration, thermal

analysis, x-ray diffraction, compressive strength, mercury intrusion porosimetry and

transport properties were evaluated at 16 hours and at 28 days. The results showed that

limestone filler can adversely affect the properties of concrete through the dilution effect.

However, heterogeneous nucleation compensates for the dilution effect at 16 hours while

the production of monocarboaluminate compensates for the dilution effect at both 16 hours

and 28 days.

Keywords: Limestone filler, compressive strength, heterogeneous nucleation, dilution,

monocarboaluminate.

2.1. Introduction

Global cement production was estimated to be 4.2 billion tonnes in 2014 due to the fact

that concrete is the second most consumed material on earth after water [1,2]. Cement

production has a significant environmental impact as it is responsible for 9% of the

worldwide manmade CO2 emission [2,3]. This is due to the fact that producing one tonne

of cement produces approximately 900 kg of CO2 of which 450 kg is produced from the

decomposition of raw materials and 360 kg from burning fuel [3]. Replacing cement with

supplementary cementing materials or fillers such as limestone filler (LF) has been one

approach to reduce the negative environmental impact of concrete [4]. In addition, LF can

reduce the cost of cement production. This is mainly due to the lower cost and hardness of

LF compared to cement clinker [5].

Limestone has been accepted as a cement replacement in many standards around the world.

For example, the use of interground limestone as a cement replacement has been accepted

in many standards in Europe since 1960, Canadian Standard Association (CSA) in 1983,

24

and ASTM C150 in 2004 [6]. However, all of these standards have set a maximum

interground limestone content which ranges from 5% to 15% [6,7].

When replacing cement, limestone influences the behavior of cement through physical and

chemical effects. The physical effect is caused by (i) modification of particle size

distribution, (ii) dilution and (iii) heterogeneous nucleation. Modification of particle size

distribution and heterogeneous nucleation can improve the properties of concrete whereas

dilution has an adverse effect. The chemical effect of limestone is caused by the chemical

reaction between limestone with monosulfate and calcium aluminate hydrate in the

hydrated cement system.

Physical Effect of Limestone

(i) Modification of the particle size distribution due to the presence of limestone is

primarily attributed to its relatively lower hardness compared to cement, and so when

ground it yields a wider particle size distribution [8]. In addition, limestone particles fill

the voids between coarser particles and thus increase the density and reduce total pores

volume of the cement system [9]. Furthermore, limestone can decrease the water demand

by replacing some of the water in the voids. This water provides additional reduction in the

friction between solid particles and thus improves the workability [10]. However, this

effect could be masked by the higher water adsorption when limestone fineness increases

[11]. When limestone particles are finer than cement, limestone can reduce the bleeding of

concrete through water adsorption at replacement levels greater than 5% [12]. At a

replacement level less than 5%, the bleeding is thought to only be influenced by the surface

area of the cement [12].

(ii) Dilution occurs when a reactive material such as cement is replaced by a nonreactive

or relatively less reactive material such as limestone [13]. Reducing the cement content

decreases the amount of hydration products and cause adverse effects on the compressive

strength at early and later ages, the porosity and the permeability of concrete. The dilution

effect masks any other limestone effects at replacement level greater than 5%. Below 5%,

the dilution effect is insignificant [14]. The dilution effect influences the properties of the

cement system at all ages. However, it is mainly observed after 3 days [15]. This can be

attributed to the heterogeneous nucleation effect of limestone which compensates for the

dilution effect at early age (i.e., before 3 days).

25

(iii) Limestone particles act as nucleation sites for the precipitation of the hydration

products [13]. However, this effect depends mainly on the fineness of limestone. The

increase in limestone fineness increases the nucleation sites for the precipitation of the

hydration products [16]. The nucleation sites provided by limestone particles allow the

hydration products to precipitate faster from the pore solution causing faster early age

strength gain [13]. In addition, the surface area of limestone particles accommodates some

of the hydration products. This reduces the thickness of the hydration products coating

unhydrated cement particles and allows faster hydration of the inner part of the cement

particles [17].

Chemical Effect of Limestone

Research studies have shown that limestone is not a chemically inert material but rather a

partially reactive material [7,10]. Limestone chemically reacts with calcium aluminate

hydrate ((CaO)3(Al2O3)·6H2O) and monosulfate ((CaO)3(Al2O3)·CaSO4·12H2O) to form

calcium monocarboaluminate (3CaO·Al2O3·CaCO3·11H2O), as presented in Equations 2.1

and 2.2 [18,19,20]. The reactions between limestone and monosulfate and calcium

aluminate hydrate take place after the exhaustion of sulfate ions in the system [21]. The

increase in limestone fineness increases the reactivity of limestone [7].


(CaO)3(Al2O3)·3CaSO4·32H2O Eq.2.1

(CaO)3(Al2O3)·6H2O + CaCO3 + 5H2O → (CaO)3(Al2O3)·CaCO3·11H2O Eq. 2.2

The influence of limestone on the concrete properties and performance have been fairly

reported in the literature [7,10,13]. However, most of the reported data are for concrete

cured at ambient temperature (i.e., 23°C) and there is limited data on the influence of

limestone under steam curing conditions [6,7,22]. While the influence of limestone is

caused by a combination of physical and chemical effects, no elaboration on the influence

of each effect has been reported. Therefore, it is essential to identify the influence of each

effect to understand how limestone interacts in the cement system and to optimize the use

of limestone for the precast/prestressed applications.

The aim of this chapter is to decouple the physical and chemical effects of LF on the

hardened and transport properties of concrete. This was achieved by using LF and an inert

26

filler (brucite, Mg(OH)2) with similar particle size distribution and fineness. Brucite (BF)

is an inert material by nature but could chemically react with the amorphous silica in fly

ash under sulfate-rich environment [23,24]. However, this condition at which BF can

chemically react does not apply in this work and therefore, BF was considered an inert

material. BF was used to evaluate and measure the combined physical effects of LF while

LF was used to measure the combined physical and chemical effects. The difference in

performance between LF and BF mixtures is attributed to the chemical reaction of LF.

Three mixtures were considered in this chapter. For each mixture, paste, mortar and

concrete were prepared. The first mixture was made of 100% of CSA type HE cement with

no interground limestone. The second and the third mixtures were made by replacing 15%

of the cement with LF and BF, respectively. The specimens were steam cured at 55°C. The

total duration of the steam curing regime was 16 hours. Following steam curing, the

specimens were moist cured in limewater until testing. The physical and chemical effects

of LF on the heat of hydration, chemical composition, compressive strength, pore size

distribution and transport properties were evaluated. The heat of hydration of cement pastes

was measured at 23°C and 55°C for a duration of 72 hours using isothermal calorimetry.

The chemical composition of cement pastes was measured at 16 hours (following steam

curing) and at 28 days (16 hours of steam curing followed by moist curing until the age of

28 days) using thermal analysis. The cube compressive strength of mortars and the concrete

compressive strength were evaluated at 16 hours and 28 days. The pore size distribution of

mortars was evaluated using mercury intrusion porosimetry (MIP) at 16 hours and 28 days.

The transport properties of cement paste, mortar and concrete were evaluated using rapid

chloride permeability test (RCPT) and sorptivity test at 16 hours and 28 days.

2.2. Experimental Program

2.2.1. Materials

Since all CSA type GU cement produced in Ontario, Canada, contains up to 5% of

interground LF, CSA type HE cement with no interground limestone was used. The cement

was supplied by Lafarge Canada Inc. The chemical and the physical properties of cement

are presented in Table 2.1. LF (97% calcium carbonate) and brucite (99% Mg(OH)2, which

will be referred to as BF) were supplied by Omya Canada Inc. and Aldon Corporation,

respectively. The selection of BF was based on the chemical reactivity and hardness. BF is

27

an inert material and has similar Mohs Hardness (i.e., 3) compared to LF [24,25]. The

hardness of BF and LF should be similar to avoid introducing a new variable in the

compressive strength results [26]. LF with nominal particle size of 3µm was selected

because it had close particle size and Blaine fineness compared to the supplied BF. LF had

a Blaine fineness of 1125 m2/kg, median particle size of 3µm and specific gravity of 2.7.

The supplied BF had a Blaine fineness of 1450 m2/kg, median particle size of 4µm and

specific gravity of 2.4. Since the particle size distribution and the Blaine fineness of the

supplied LF and BF were slightly different, both materials required modification in the

particle size distribution to achieve similar particle size distribution and Blaine fineness.

This modification consisted of sieving LF and BF using 10µm, 7µm, 5µm and 2µm sieves

and using equal proportion retained on each sieve. The sieving was conducted to ensure

similar particle size distribution of LF and BF. In addition, the portion of LF passing 2µm

sieve was ground so that the final LF product has a Blaine fineness of 1450 ± 30 m2/kg

which is similar to BF. The particle size distribution of cement, LF and BF is presented in

Figure 2.1. The fine aggregate was natural sand with a specific gravity of 2.72 and a

fineness modulus of 2.84. The coarse aggregate was crushed limestone with a maximum

size of 13 mm. The sand and coarse aggregates were supplied by Dufferin Aggregates.

Plastol 6400, a high-range water reducer (HRWR), supplied by Euclid Chemical was used.

Table 2.1: Chemical and Physical Properties of Cement

Chemical and Physical Properties HE Cement

SiO2 (%) 19.7

Al2O3 (%) 5.0

Fe2O3 (%) 3.3

CaO (%) 61.8

MgO (%) 2.5

SO3 (%) 4.1

Na2Oeq (%) 0.7

C3S (%) 54.0

C3A (%) 8.0

C4AF (%) 10.0

C2S (%) 14.0

LOI at 1150 °C (%) 0.9

Blaine (m2/kg) 505

28

Figure 2.1: Particle Size Distribution of Cement, LF and BF

2.2.2. Mix Designs

Three mix designs were prepared. For each mix design, cement paste, mortar and concrete

were prepared. The details of the mixtures are presented in Table 2.2 for cement paste and

mortar mixes and Table 2.3 for concrete mixes. LF and BF were used to replace 15% by

weight of the cement. The water-to-cement ratio (w/c) was kept constant in paste, mortar

and concrete at 0.34 to represent the w/c used in SCC. LF and BF were not considered a

cementing material in w/c calculations. No HRWR was used in cement pastes to prevent

any alteration in the results of heat of hydration or thermal analysis. The sand-to-cement

ratio in the mortar mixtures was 2. Concrete had total cement and coarse aggregate contents

of 450 kg/m3 and 900 kg/m3, respectively. Concrete mixing was done in a 30-litre drum

mixer.

0

10

20

30

40

50

60

70

80

90

100

1 10 100

Per

centa

ge

Pas

sing (

%)

Particle Size (µm)

Cement LF and BF

29

Table 2.2: Cement Paste and Mortar Mixture Details

Mix

ID

Cement

(% by

weight)

Cement

Replacement

(% by weight)

Sand/Cement

Ratio for

Mortar

w/c

Ratio

LF BF

C 100 0 0 2

0.34 LF 85 15 0 2

BF 85 0 15 2

Table 2.3: Concrete Mix Designs

Mix

ID

Cement LF BF Coarse

Agg.

Fine

Agg. Water HRWR

(ml/100kg) kg/m3

C 450.0 0 0 900 920 153.0 300

LF 382.5 67.5 0 900 955 130.1 1200

BF 382.5 0 67.5 900 945 130.1 1200

2.2.3. Curing Regime

Paste, mortar and concrete specimens were steam cured at 55°C and 95% relative humidity

(RH) for 16 hours, as presented in Figure 2.2. A 0.45 m3 environmental chamber

manufactured by Cincinnati Sub-Zero was used. The relative humidity in the chamber was

controlled by a steam generator built into the chamber. A maximum curing temperature of

55°C was used in order to prevent any alteration in the microstructure due to delayed

ettringite formation [27]. Following steam curing, the specimens were moist cured in

limewater at 23°C until tested.

30

Figure 2.2: Steam Curing Regime

2.2.4. Test Methods

Cement paste specimens were used for heat of hydration, thermal analysis and transport

properties measurements. Mortar specimens were used for cube compressive strength, MIP

and transport properties testing. Concrete specimens were used to measure the compressive

strength and transport properties.

Heat of Hydration: For each mixture, three cement paste samples were tested for the heat

of hydration at 23°C and 55°C over a period of 72 hours in accordance with ASTM C1702-

09 Method B. A TAM Air isothermal calorimeter manufactured by Thermometric was used

to test the cement pastes at 23°C. At 55°C, I-Cal 8000 isothermal calorimeter manufactured

by Calmetrix was used. Before mixing the cement pastes, all materials were preconditioned

to a temperature within ± 2°C of the isothermal calorimeter testing temperature. This was

done by placing the materials in the environmental chamber set at ± 2°C of the isothermal

calorimeter testing temperature for 2 hours.

Thermal Analysis: Calcium hydroxide (Ca(OH)2), calcium carbonate (CaCO3) and

magnesium hydroxide (Mg(OH)2) contents were measured at 16 hours and 28 days using

Thermal Gravimetric /Differential Thermal Analysis (TG/DTA). For each mix design, two

TG/DTA tests were conducted. The tests were conducted using Netzsch SA Simultaneous

10

15

20

25

30

35

40

45

50

55

60

0 2 4 6 8 10 12 14 16 18

Tem

per

ature

(°C

)

Time (hour)

Curing Regime Internal Temperature of Specimens

95% RH

31

Thermal Analyzer heated to 1100°C at a heating rate of 10°C/min. Ca(OH)2 content was

used to evaluate the hydration products for each mixture. The paste samples were freeze-

dried until a constant mass. In the freeze-drying process, the samples were frozen in liquid

nitrogen to stop the hydration reactions. After that, the samples were placed in a sealed

desiccator under vacuum at -10°C. The samples were freeze-dried until a constant mass

(less than 0.1% change in a 24-hour period) was achieved.

CaCO3 content was used to calculate the amount of LF that was consumed in the chemical

reaction. The initial CaCO3 content (prior to mixing), expressed in percentage by weight

(wt%), was calculated according to Equation 2.3. The final CaCO3 content was calculated

using TG/DTA mass loss at approximately 680 to 800°C, as presented in Equation 2.4 [28].

The amount of reacted LF was calculated using Equation 2.5.

Initial CaCO3 Content (wt%) = 𝑀𝑎𝑠𝑠 𝑜𝑓 𝐿𝐹

𝑇𝑜𝑡𝑎𝑙 𝑀𝑎𝑠𝑠 (𝑐𝑒𝑚𝑒𝑛𝑡+𝐿𝐹+𝑤𝑎𝑡𝑒𝑟)× 100 Eq.2.3

Final CaCO3 Content (wt%) = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (680 − 800°C ) ×Molar Mass of CaCO3

Molar Mass of CO2 Eq. 2.4

Reacted LF (wt%) = Initial CaCO3 content – Final CaCO3 content Eq.2.5

Similarly, the initial content of BF was calculated using Equations 2.6. Mass loss

corresponding to the decomposition of BF between 350 and 400°C was used to calculate

the final BF content, as presented in Equation 2.7 [28]. Ca(OH)2 content was measured

using TG/DTA mass loss between 450 to 500°C, as presented in Equation 2.8 [28].

Initial BF Content (wt%) = 𝑀𝑎𝑠𝑠 𝑜𝑓 Mg(OH)2

𝑇𝑜𝑡𝑎𝑙 𝑀𝑎𝑠𝑠 (𝑐𝑒𝑚𝑒𝑛𝑡+𝑀𝑔+𝑤𝑎𝑡𝑒𝑟)× 100 Eq.2.6

Final BF Content (wt%) = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (350 − 400°C ) ×Molar Mass of Mg(OH)2

Molar Mass of H2O Eq. 2.7

Measured Ca(OH)2 Content (wt%) = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (450 − 500°C ) ×Molar Mass of Ca(OH)2

Molar Mass of H2O

Eq. 2.8

X-Ray Diffraction: The x-ray diffraction was used to identify the calcium

monocarboaluminate phase. At 28 days, paste samples were dried in a vacuum oven at

38°C for 24 hours. Prior to x-ray testing, the samples were crushed and sieved to obtain a

powder with particle size of less than 45μm.

32

Mortar Compressive Strength: The cube compressive strength of mortar samples was

measured in accordance with ASTM C109-12. For each mortar mixture, three cubes were

tested at 16 hours and at 28 days.

MIP: The pore size distribution and the total porosity of mortars were measured using MIP.

The Samples were pressurized up to 413 MPa using automated porosimeter manufactured

by Quantachrome Instruments. Before testing, the samples were freeze-dried until a

constant mass (less than 0.1% change in a 24-hour period) was achieved.

Concrete Compressive Strength: The compressive strength of concrete was measured using

200 mm × 100 mm cylinders at 16 hours and 28 days [29]. For each mix design, three

cylinders were tested at each age.

Transport Properties: The transport properties of cement paste, mortar and concrete

specimens were evaluated using RCPT and sorptivity at 16 hours and 28 days. The RCPT

were conducted in accordance with ASTM C 1202 and sorptivity tests were conducted

according to ASTM C 1585. For each test, three concrete samples were tested and the

average value is reported.

2.3. Results and Discussion

2.3.1. Heat of Hydration

The total heat released during the first 40 hours of hydration from each paste cured at 23°C

and 55°C is presented in Figure 2.3. At a curing temperature of 23°C, during the first 12

hours of hydration, mixes made with LF and BF showed higher total heat released

compared to the control mixture made of 100% cement. At approximately 14 hours, the

total heat released from all mixes were similar. After 14 hours, the control mixture made

of 100% cement showed higher total heat released compared to mixes made with LF and

BF. At a curing temperature of 55°C, mix LF showed higher total heat released compared

to mix BF and the control mixture made of 100% cement. Mix BF showed higher total heat

released in the first 18 hours of hydration compared to the control mixture made of 100%

cement. After 18 hours, mixes made with BF and 100% cement had similar total heat

released. The increase in the total heat released of HE cement paste with the addition of

fine particles (i.e., LF and BF) was due to the acceleration in the hydration reactions which

is in alignment with the literature [30,31,32]. The precipitation of the hydration products

33

from the pore solution is assumed to be similar on the surface of LF and BF particles since

both materials have similar physical characteristics.

The physical effect of LF (the difference in the results between the control mixture made

of 100% cement and mix BF) increased the heat of hydration compared to the control

mixture made of 100% cement. This increase is caused by the heterogeneous nucleation

which causes acceleration in the hydration rate. The chemical effect of LF (the difference

in the results between mix LF and mix BF) showed an additional increase in the heat of

hydration. This increase in heat of hydration was caused by the chemical reaction of LF,

which is an exothermic chemical reaction [33]. The combined effect (physical and

chemical) of LF was influenced by curing temperature. This was evident in total heat

released after 40 hours where LF reduced the total heat released when cured at 23°C and

increased the total heat released at 55°C compared to the control mixture made of 100%

cement.

Figure 2.3: Effect of Curing Temperature (23°C and 55°C) on the Total Heat Released of

Cement Pastes

0

50

100

150

200

250

0 5 10 15 20 25 30 35 40

Ener

gy (

J/g)

Time (hours)

C-23°C LF-23°C BF-23°C

C-55°C LF-55°C BF-55°C

23°C

55°C

34

2.3.2. Thermal Analysis

The thermal analysis was conducted to measure the amount of reacted LF and to confirm

that BF is a chemically inert material. In addition, a relative evaluation of the hydration

products was conducted using Ca(OH)2 content. The mass loss from TG analysis and the

DTA results are presented in Figures 2.4 and 2.5, respectively. Figure 2.4 presents the mass

loss with temperature. Figure 2.5(a) presents DTA results for the control mixture made

with 100% cement while Figures 2.5(b) and (c) present DTA results for mixes made with

LF and BF, respectively (please refer to Section A.5 in Appendix A for the raw data and

the statistical analysis). Based on the measured data, Ca(OH)2, CaCO3 and BF contents

were calculated using Equations 2.3 through 2.8. The results in Figures 2.4 and 2.5(b)

showed that the addition of LF increased the Ca(OH)2 content at 16 hours compared to the

control mixture made with 100% cement. The content of Ca(OH)2 increased from 7.4 wt%

in the control mixture made of 100% cement to 8.6 wt% in mix LF. This is expected as the

additional surface area provided by LF acts as nucleation sites for the precipitation of the

hydration products. This accelerates the hydration process resulting in a higher Ca(OH)2

content in mix LF compared to the control mixture made of 100% cement. At 28 days, the

Ca(OH)2 content in mix LF and the control mixture made of 100% cement were

approximately similar (11.9 wt% in the control mixture made of 100% cement and 12.2

wt% in mix LF). CaCO3 content was corrected for LF purity (since the purity of LF was

97% not 100%) and the initial carbonation of the cement. The amount of LF that was

consumed in the reaction in mix LF was 1.3 wt% at 16 hours and 2.4 wt% at 28 days.

Dividing the amount of reacted LF by the initial CaCO3 content yields the percentage of

reacted LF to the total available LF in the system (i.e., 11.0% at 16 hours and 20.9% at 28

days). The amount of reacted LF at 16 hours was approximately 53% of the amount of

reacted LF at 28 days. This indicates that the reaction of LF took place early during the

hydration process and explains the higher heat of hydration in mix LF compared to mix BF

and the control mixture made of 100% cement.

35

Figure 2.4: Effect of Mixture Design on the TG Mass Loss of Cement Pastes at 16 hours

and 28 days

The addition of BF also increased Ca(OH)2 content at 16 hours compared to the control

mixture made of 100% cement, as presented in Figures 2.4 and 2.5(c). The content of

Ca(OH)2 increased from 7.4 wt% in the control mixture made of 100% cement to 8.2 wt%

in mix BF. This is due to the additional surface area provided by BF that acts as nucleation

sites for the precipitation of the hydration products. At 28 days, mix BF and the control

mixture made of 100% cement showed similar Ca(OH)2 content (11.9 wt%). Based on the

mass loss attributed to the decomposition of BF, the final BF content calculated based on

equation 2.7 was 11.6 wt% regardless of testing age (i.e., 16 hours or 28 days). The initial

and final BF content was similar (11.6 wt%). This confirms the chemically inert behaviour

of BF.

70

75

80

85

90

95

100

0 200 400 600 800 1000

Mas

s L

oss

(%

)

Temperature (°C)

C- 16 hours LF-16 hours BF-16 hours

C- 28 days LF-28 days BF-28 days

16 Hrs.

28 Days

36

Figure 2.5: Effect of Mixture Design on DTA Results of Cement Pastes at 16 hours and

28 days (a) 100% Cement, (b) LF and (c) BF

2.3.3. X-Ray Diffraction

The x-ray diffraction was used to confirm the presence of calcium monocarboaluminate in

the hydrated cement paste in mix LF. Figure 2.6 presents the x-ray diffraction results for

the control mix, as presented in Figure 2.6.a and LF mix, as presented in Figure 2.6.b. The

results showed that a peak at approximately 12° 2θ representing calcium

monocarboaluminate was observed in mix LF while no peak was observed in the x-ray

diffraction results of the control mix.

-0.4

-0.2

0.0

0.2

0.4

0.6

0 100 200 300 400 500 600 700 800 900 1000

DT

A/(

µV

/mg)

Temperature (°C)

16 hours

28 days

(a)

Ca(OH)2 decomposition

-0.4

-0.2

0.0

0.2

0.4

0.6

0 100 200 300 400 500 600 700 800 900 1000

DT

A/(

µV

/mg)

Temperature (°C)

16 hours

28 days

(b)


CaCO3 decomposition

-0.4

-0.2

0.0

0.2

0.4

0.6

0 100 200 300 400 500 600 700 800 900 1000

DT

A/(

µV

/mg)

Temperature (°C)

16 hours

28 days

(c)


Mg(OH)2 decomposition

37

E = Ettringite, MS = Monosulfate, MC = Monocarboaluminate

Figure 2.6: X-Ray Diffraction Analysis of Cement Pastes at 28 days (a) 100% Cement

and (b) LF

2.3.4. Mercury Intrusion Porosimetry

The addition of LF and BF reduced the total porosity at 16 hours compared to the control

mixture made of 100% cement, as presented in Figure 2.7 (please refer to Section A.5 in

Appendix A for the raw data and the statistical analysis). The total porosity of the control

mixture made of 100% cement was 9.3% whereas mix LF and mix BF showed total

porosities of 7.9% and 8.7%, respectively. This is expected as the fine particles of LF or

BF fill the voids between the coarser cement and sand particles and reduce the total

porosity. In addition, the increase in the hydration products including Ca(OH)2 with the

addition of LF and BF reduces the total porosity. Furthermore, the chemical effect of LF

(the difference in the results between mix LF and mix BF) reduced the porosity due to the

production of monocarboaluminate. However, at 28 days, the total porosity of all mixes

was approximately the same (5.8% to 6.2%). Two of the physical effects of LF

(heterogeneous nucleation and modification of particle size distribution) in conjunction

5 7 9 11 13 152θ

E

MS

(a)

5 7 9 11 13 15

2θ

E

MC

(b)

38

with the chemical effect of LF reduced the porosity at 16 hours. However, due to the

dilution effect, the enhancement in the microstructure observed at 16 hours was diminished

at 28 days.

Figure 2.7: Effect of Mixture Design on the Void Size Distribution in Mortars at 16

Hours and 28 Days

Figure 2.7 presents the pore size distribution of mortars at 16 hours and 28 days. At 16

hours, pores larger than 0.01 µm were significantly less in mix LF and mix BF compared

to the control mixture made of 100% cement. Mixes LF and BF showed similar pore

volume distributions between 4 µm and 0.05 µm. However, the volume of pores smaller

than 0.05 µm was less in mix LF compared to mix BF. At 28 days, the pore size distribution

of control mixture made of 100% cement and mix BF were similar. For mix LF, the volume

of pores larger than 0.03µm was less compared to the control mixture made of 100%

cement and mix BF, as presented in Figure 2.7.

2.3.5. Compressive Strength of Mortar and Concrete

The cube compressive strengths of mortars at 16 hours and 28 days are presented in Figure

2.8 (please refer to Section A.5 in Appendix A for the raw data and the statistical analysis).

Each column in Figure 2.8 is the average of three tests. The coefficients of variation were

0.00

0.02

0.04

0.06

0.08

0.10

0.0010.010.1110

Po

re V

olu

me

Pore Size (µm) - Log Scale

C- 16 hours LF- 16 hours BF- 16 hours

C- 28 days LF- 28 days BF- 28 days

39

below 5%. At 16 hours, the addition of LF and BF increased the cube compressive strength

by 7% and 3%, respectively, compared to the control mixture made of 100% cement. At

28 days, the strength of all mixes was approximately similar (90 to 94 MPa).

Figure 2.8: Effect of Effect of LF and BF Filler on the Cube Compressive Strength of

Mortars at 16 Hours and 28 Days Compared to Control Mix

The compressive strengths of concrete mixtures are presented in Figure 2.9 (please refer to

Section A.5 in Appendix A for the raw data and the statistical analysis). Each column in

Figure 2.9 is the average of three tests whereas the coefficients of variation were below

3%. The addition of LF improved the 16-hour compressive strength by 8% compared to

the concrete mixture made with 100% cement. Concrete mixtures made with BF showed

5% increase in the compressive strength compared to the concrete mixture made with 100%

cement. At 28 days, the compressive strength of all concrete mixtures ranged between 82

and 85 MPa.

55

60

65

70

75

80

85

90

95

100

16 hours 28 days

Cub

e C

om

pre

ssiv

e S

tren

gth

(M

Pa)

Age

C LF BF

40

Figure 2.9: Effect of LF and BF Filler on the Concrete Compressive Strength at 16 Hours

and 28 Days Compared to Control Mix

The results of the compressive strength of mortar and concrete specimens are in agreement.

The increase in the 16-hour compressive strength with the addition of BF (i.e., the physical

effect of LF) was caused by two factors. Firstly, the fine particles of BF fill the voids

between the larger particles, which reduces the porosity and increase the strength.

Secondly, the increase in hydration rate with the addition of BF increases the hydration

products and thus reduces the porosity and increase the strength. This agrees with the

results obtained from the heat of hydration, thermal analysis and MIP. The chemical effect

of LF (i.e., the difference between mix LF and mix BF) increased the strength at 16 hours.

Although a distinct effect of LF and BF was observed in heat of hydration, thermal analysis,

MIP and compressive strength results at 16 hours, no effect was observed at 28 days. This

is due to the dilution effect which is in alignment with the literature [13,14,15].

2.3.6. Transport Properties

The transport properties including RCPT and sorptivity test were conducted on paste,

mortar and concrete specimens. The purpose of testing the transport properties of cement

paste, mortar and concrete is to evaluate the influence of LF on the microstructure of the

55

60

65

70

75

80

85

90

16 hours 28 days

Co

ncr

ete

Co

mp

ress

ive

Str

ength

(M

Pa)

Age

C LF BF

41

cement system in the presence of aggregate (i.e., sand particles in mortars and sand and

coarse aggregates particles in concrete).

The RCPT values are presented in Table 2.4. Each value in the table is the average of three

tests. The coefficients of variation were below 4% (please refer to Section A.5 in Appendix

A for the raw data and the statistical analysis). Paste specimens showed the highest RCPT

values followed by mortar and concrete specimens. This is due the fact that the electrical

charge (Coulombs) passes mainly through the saturated capillary pores in the cement paste

[34]. Therefore, the addition of sand in mortar or sand and coarse aggregate in concrete

reduces the volume proportion of the cement paste and thus reduces the RCPT values, as

presented in Table 2.4. The maximum temperature reached during the test ranged from

38°C to 46°C in concrete specimens, 42°C to 56°C in mortar specimens and 57 to 68°C in

paste specimens. This is expected as the increases in the electrical charge passing through

the RCPT specimen increases the temperature of the specimen. The maximum temperature

in pastes specimens was less than the 80°C limit required to prevent any damage to the

RCPT cell. The addition of LF or BF reduced the RCPT values at 16 hours and 28 days

compared to the control mixture made of 100% cement. The reduction in the RCPT values

when LF and BF were used was below 9% at 16 hours regardless of specimen’s type (i.e.,

paste, mortar and concrete). However, at 28 days, LF caused a significant reduction in the

RCPT values (12%, 21% and 28% in paste, mortar and concrete specimens, respectively).

The reduction in the RCPT values when BF was used was 5%, 11% and 14% in paste,

mortar and concrete specimens, respectively.

The initial sorptivity results are presented in Table 2.5. Each value in the table is the

average of three tests. The coefficients of variation were below 5% (please refer to Section

A.5 in Appendix A for the raw data and the statistical analysis). The initial sorptivity results

were higher in the paste specimens followed by mortar and concrete specimens. This is due

to the fact that water is absorbed through the paste portion of the specimen. Since paste

specimens have the highest paste volume followed by mortar and concrete specimens (as

presented in Table 2.5), the sorptivity is expected to be the highest in paste specimens

followed by mortar and concrete specimens. The addition of LF reduces the initial

sorptivity at 16 hours and 28 days compared to the control mixture made with 100%

cement. The reduction in the initial sorptivity was approximately 5% at 16 hours regardless

of specimen type (i.e., paste, mortar and concrete). At 28 days, the reduction in the initial

42

sorptivity was 9% in paste, 12% in mortar and 14% in concrete specimens. The addition of

BF decreased the initial sorptivity by approximately 5% at 28 days while no significant

effect was observed at 16 hours compared to the control mixture made of 100% cement.

The reduction in the transport properties in the presence of LF (i.e., physical effect) at 16

hours was likely caused by the ability of LF to fill the voids between coarser particles,

accelerate the hydration rate, and produce calcium monocarboaluminate that fills the voids

and reduces the permeability. The chemical effect of LF (i.e., the difference between mix

LF and mix BF) was greater at 28 days compared to 16 hours. This is due to the increase

in the amount of reacted LF that produces calcium monocarboaluminate, which fills the

voids and reduces the permeability. By comparing Tables 2.4 and 2.5, it was observed that

the sorptivity test was less sensitive to the change in specimen type (i.e., paste, mortar and

concrete) compared to RCPT.

Table 2.4: RCPT Values of Paste, Mortar and Concrete Specimens

Mix ID Paste Volume

(%)

RCPT (Coulombs)

Paste

16 hours Difference (%) 28 days Difference (%)

C 100 11338 --- 8850 ---

LF 92 10149 -10.5 7783 -12.1

BF 92 10633 -6.2 8388 -5.2

Mortar


C 47.1 4947 --- 3005 ---

LF 45.4 4580 -7.4 2390 -20.5

BF 45.4 4800 -3.0 2665 -11.3

Concrete


C 29.8 2840 --- 1226 ---

LF 25.9 2500 -12.0 882 -28.1

BF 25.9 2760 -2.8 1051 -14.3

43

Table 2.5: Initial Sorptivity Results of Paste, Mortar and Concrete Specimens

Mix ID Paste Volume

(%)

Initial Sorptivity (×10-4 mm/sec0.5)

Paste


C 100 25.6 --- 15.3 ---

LF 92 24.5 -4.3 14.0 -8.6

BF 92 25.1 -2.0 15.0 -2.2

Mortar


C 47.1 16.2 --- 14.8 ---

LF 45.4 15.2 -6.0 13.0 -12.2

BF 45.4 16.0 -1.1 14.0 -5.3

Concrete


C 29.8 11.8 --- 10.1 ---

LF 25.9 11.2 -5.4 8.7 -14.1

BF 25.9 11.8 -0.5 9.5 -6.5

2.3.7. Physical and Chemical Effects of Limestone Filler

As mentioned earlier, LF has physical and chemical effects that influence the properties of

concrete. These effects occur simultaneously and it is difficult to evaluate the contribution

of each effect individually. However, by using an inert material such as BF with similar

physical properties to LF, the physical and chemical effects of LF could be decoupled. The

thermal analysis confirmed the chemically inert behavior of BF. The difference in

performance between mix LF (i.e., combined physical and chemical effects) and mix BF

(i.e., physical effect) defines the influence of the chemical effect of LF (i.e., calcium

monocarboaluminate). In the following discussion, the combined effect of modification of

particle size distribution, dilution and heterogeneous nucleation is referred to as the

physical effect of LF whereas the chemical reaction of LF is referred to as the chemical

effect of LF.

To clearly evaluate the influence of the physical and chemical effects of LF, the difference

in the results between the control mixture made of 100% cement and mix LF and mix BF

is presented in Figure 2.10 for tests conducted at 16 hours and in Figure 2.11 for tests

conducted at 28 days. In these figures, each column presents the percentage difference in

the test results between mix LF and mix BF (i.e., the chemical effect of LF presented in the

44

grey portion of the column) and the percentage difference in tests results between the

control mixture made of 100% cement and mix BF (i.e., the physical effect of LF presented

in the white portion of the column).

Figure 2.10: Physical and Chemical Effect of LF at 16 Hours

At 16 hours, the physical and chemical effects of LF increased the compressive strength of

mortar and concrete, reduced the total porosity and reduced the RCPT and sorptivity of

cement paste, mortar and concrete, as presented in Figure 2.10. However, the contribution

of each effect was not similar in all tests. The chemical effect of LF had greater influence

in reducing the total porosity compared to the physical effect. Although the physical and

the chemical effects of LF had approximately similar influence on the transport properties

of cement pastes, the chemical effect of LF had a greater influence on the transport

properties of mortar and concrete compared to the physical effect of LF.

At 28 days, the physical effect of LF had a negative impact on the compressive strength of

mortar and concrete, as presented in Figure 2.11. To the contrary, the chemical effect of

-6.3

2.85.1

-6.2-3.0 -2.8 -2.0

-1.1 -0.5

-10.0

4.43.2

-4.3

-4.4-9.2

-2.3 -4.9 -4.9

-30

-25

-20

-15

-10

-5

0

5

10

15

Tota

l P

oro

sity

Cu

be

Co

mp.

Str

eng

th

Co

ncr

ete

Com

p.

Str

eng

th

RC

PT

- P

aste

RC

PT

- M

ort

ar

RC

PT

- C

oncr

ete

Sorp

tiv

ity-

Pas

te

Sorp

tiv

ity-

Mo

rtar

Sorp

tiv

ity-

Co

ncr

ete

Dif

fere

nce

Co

mp

ared

to

Mix

C (

%)

Physical Effect Chemical Effect

45

LF increased the compressive strength of mortar and concrete. The physical and chemical

effects of LF showed a similar reduction in RCPT and sorptivity values regardless of

specimen type (i.e., paste, mortar or concrete). The reduction in the RCPT and sorptivity

values due to the addition of LF (i.e., combined physical and chemical effects) was greater

in concrete followed by mortar and paste specimens. This could be attributed to the

presence of interfacial transition zone in mortar and concrete that was densified by the

presence of fine particles of LF [35].

Figure 2.11: Physical and Chemical Effect of LF at 28 Days

It is evident that LF reduces the porosity, increases the compressive strength and reduces

the transport properties of the cement system through physical and chemical effects. The

physical effect of LF had a greater influence on the compressive strength of mortar and

concrete at 16 hours compared to 28 days. This could be due to the dilution effect which is

more pronounced at 28. In addition, a portion of the dilution effect was compensated for

by the acceleration in the hydration reactions at early age (i.e., at 16 hours). The

improvement in the transport properties due to the chemical effect of LF at 28 days was

-2.2 -4.1 -5.2

-11.3 -14.3

-2.2-5.3 -6.5

4.8 2.9

-6.8

-9.2

-13.8

-6.4

-6.9-7.6

-30

-25

-20

-15

-10

-5

0

5

10

15

20

Cu

be

Co

mp.

Str

eng

th

Co

ncr

ete

Com

p.

Str

eng

th

RC

PT

- P

aste

RC

PT

- M

ort

ar

RC

PT

- C

oncr

ete

Sorp

tiv

ity-

Pas

te

Sorp

tiv

ity-

Mo

rtar

Sorp

tiv

ity-

Co

ncr

ete

Dif

fere

nce

Co

mp

ared

to

Mix

C (

%)

Physical Effect Chemical Effect

46

greater than 16 hours. This is due to the increase in the calcium monocarboaluminate

content at 28 days. Calcium monocarboaluminate fills the voids and enhances the

microstructure. This enhancement was in pores less than 0.1µm and clearly observed at 16

hours, as presented in Figure 2.12. Figure 2.12 is a representation of the cumulative pore

size distribution for mixes C, LF and BF at 16 hours adapted from Figure 2.7. The interface

between the hashed pattern and the vertical lines patters in Figure 2.12 represents mix BF

from Figure 2.7. The lower boundary in Figure 2.12 represents mix LF in Figure 2.7.

Figure 2.12: Physical and Chemical Effect of LF on Pore Size Distribution at 16 Hours

The chemical reaction of LF is increased with the increase in LF fineness. Similarly,

increasing LF fineness increases the heterogeneous nucleation (i.e., accelerate the

hydration reaction) and the modification in the particle size distribution of cement system.

Therefore, it would be expected that using finer LF (i.e., finer than 3µm) will yield even

greater positive effect on the mechanical and transport properties of paste, mortar and

concrete compared to what was observed in results of this study.

2.4. Conclusions

Based on the results of this chapter, the following conclusions can be drawn:

(i) The physical effect of limestone filler increases the compressive strength of mortar

and concrete at 16 hours. This increase is due to the acceleration in the hydration

0.00

0.02

0.04

0.06

0.08

0.10

0.0010.010.1110

Po

re V

olu

me

Pore Size (µm) Log Scale

Chemical Effect of LF

Physical Effect of LF

Mix C

47

rate and the reduction in the porosity. However, the increase in the compressive

strength of mortar and concrete was diminished at 28 days due to the dilution effect.

(ii) The chemical and physical effects of limestone filler have similar contributions in

reducing the transport properties of cement paste, mortar and concrete.

(iii) The reactivity of limestone filler and the production of calcium

monocarboaluminate had an important role in enhancing the compressive strength

and microstructure of mortar and concrete specimens at 16 hours and at 28 days.

(iv) The dilution effect adversely affected the mechanical properties of concrete at 28

days. However, the modification of particle size distribution caused by limestone

filler and the production of calcium monocarboaluminate compensated for the

dilution effect.

2.5. References

[1]. U.S. Department of Interior and U.S. Geological Survey (2015). Mineral Commodity

Summaries.

[2]. PBL Netherlands Environmental Assessment Agency, Trends in global CO2

Emissions: 2015 Report, PBL 1803, pp. 1–10.

[3]. Benhelal, E., Zahedi, G., Shamsaei, E., and Bahadori, A. (2013). Global Strategies

and Potentials to Curb CO2 Emissions in Cement Industry. Journal of Cleaner

Production, Vol. 51, pp. 142–161.

[4]. Celik, K., Meral, C., Petek, A., Gursel, A., Mehta, P., Horvath, A., and Monteiro, P.

(2015). Mechanical Properties, Durability, and Life-cycle Assessment of Self-

Consolidating Concrete Mixtures Made with Blended Portland Cements Containing

Fly Ash and Limestone Powder. Cement and Concrete Composites, Vol. 56, pp. 59–

72.

[5]. Bentz, D., Irassar, E., Bucher, B., and Weiss, W. (2009). Limestone Fillers Conserve

Cement: Part 1: An Analysis Based on Power’s Model. Concrete International, pp.

41–46.

[6]. Tennis, P.D., Thomas, M.D.A., and Weiss, W.J. (2011). State-of-the-art Report on

Use of Limestone in Cements at Levels of up to 15 %, PCA R&D SN3148, Portland

Cement Association.

48

[7]. Hooton, R.D., Nokken, M., and Thomas, M.D.A. (2007). Portland-limestone

Cement: State-of-the-art Report and Gap Analysis for CSA A 3000. SN3053, Cement

Association of Canada, pp. 1–59.

[8]. Gunnelius, K.R., Lundin, T.C., Rosenholm, J.B., and Peltonen, J. (2014). Rheological

Characterization of Cement Pastes with Functional Filler Particles. Cement and


[9]. Chen, J., Kwan, A., and Jiang, Y. (2014). Adding Limestone Fines as Cement Paste

Replacement to Reduce Water Permeability and Sorptivity of Concrete. Construction

and Building Materials, Vol. 56, pp. 87–93.

[10]. Hawkins, P., Tennis, P., and Detwiler, R. (2003). The Use of Limestone in Portland

Cement: A State-of-the-art Review. Portland Cement Association, Skokie, IL, USA.

[11]. Schmidt, M. (1992). Cement with Interground Additives - Capabilities and

Environmental Relief: Part 1. Zement-Kalk-Gips, Vol. 45, No. 4, pp. 87–92.

[12]. Mohammadi, I., and South, W. (2015). Decision-making on Increasing Limestone

Content of General Purpose Cement. Journal of Advanced Concrete Technology,

Vol. 13, pp. 528–537.

[13]. Irassar, E.F. (2009). Sulfate Attack on Cementitious Materials Containing Limestone

Filler - A Review. Cement and Concrete Research, Vol. 39, No. 3, pp. 241–254.

[14]. Tsivilis, S., Tsantilas, J., Kakali, G., Chaniotakis, E., and Sakellariou, A. (2003). The

Permeability of Portland Limestone Cement Concrete. Cement and Concrete

Research, Vol. 33, No. 9, pp. 1465–1471.

[15]. Kenai, S., Soboyejo, W., and Soboyejo, A. (2004). Some Engineering Properties of

Limestone Concrete. Materials and Manufacturing Processes, Vol. 19, No. 5, pp.

949–961.

[16]. Knop, Y., and Peled, A. (2016). Setting Behaviour of Blended Cement with

Limestone: Influence of Particle Size and Content. Materials and Structures, Vol. 49,

pp. 439–452.

[17]. Lin, F., and Meyer, C. (2009). Hydration Kinetics Modeling of Portland Cement

Considering the Effects of Curing Temperature and Applied Pressure. Cement and


[18]. Kakali, G., Tsivilis, S., Aggeli, E., and Bati, M. (2000). Hydration Products of C3A,

C3S and Portland Cement in the Presence of CaCO3. Cement and Concrete Research,

Vol. 30, No. 7, pp. 1073–1077.

49

[19]. Bentz, D. (2006). Modeling the Influence of Limestone Filler on Cement Hydration


[20]. Kuzel, H., and Baier, H. (1996). Hydration of Calcium Aluminate Cements in the


141.

[21]. Wang, J. (2010). Hydration Mechanism of Cements Based on Low-CO2 Clinkers

Containing Belite, Ye’elimite and Calcium Alumino-Ferrite. Journal of Materials

Chemistry, Universit´e des Sciences et Technologie de Lille - Lille I.

[22]. Ramezanianpour, A.M., and Hooton, R.D. (2013). Sulfate Resistance of Portland-

limestone Cements in Combination with Supplementary Cementitious Materials.

Materials and Structures, Vol. 46, No. 7, pp. 1061–1073.

[23]. Zhang, T., Vandeperre, L., and Cheeseman, C. (2014). Formation of Magnesium

Silicate Hydrate (M-S-H) Cement Pastes using Sodium Hexametaphosphate. Cement

and Concrete Research, Vol. 65, pp. 8–14.

[24]. Moore, J., Stanitski, C., and Jurs, P. (2009). Principles of Chemistry: The Molecular

Science. 1st Edition, Brooks Cole, USA, pp. 143–148.

[25]. Santhanam, M. (2013). Performance of Cement-based Materials in Aggressive

Aqueous Environments. RILEM State-of-the-Art Reports, Vol. 10, pp. 75–90.

[26]. Zhange, P., Li, S., and Zhange, Z. (2011). General Relationship between Strength

and Hardness. Materials Science and Engineering: A, Vol. 529, pp. 62–73.

[27]. Brunetaud, X., Linder, R., Divet, L., Duragrin, D., and Damidot, D. (2007). Effect of


Ettringite Formation. Materials and Structures, Vol. 40, No. 6, pp. 567–578.

[28]. Maria, F. (2011). Handbook of Thermogravimetric System of Minerals and its Use

in Geological Practice. Geological Institute of Hungary, Budapest, Hungary, pp. 13–

55.

[29]. CSA A23.1/A23.2 (2014). Concrete Materials and Methods of Concrete

Construction/Test Methods and Standard Practices for Concrete, Canadian Standards

Association, Toronto, Canada.

[30]. Kumar, A., Oey, T., Falla, G.P., Henkensiefken, R., Neithalath, N., and Sant, G.

(2013). A Comparison of Intergrinding and Blending Limestone on Reaction and

Strength Evolution in Cementitious Materials. Construction and Building Materials,

Vol. 43, pp. 428–435.

50

[31]. Ye, G., Liu, X., De Schutter, G., Poppe, M., and Taerwe, L. (2007). Influence of

Limestone Powder Used as Filler in SCC on Hydration and Microstructure of Cement

Pastes. Cement and Concrete Composites, Vol. 29, No. 2, pp. 94–102.

[32]. Pera, J., Husson, S., and Guilhot, B. (1999). Influence of Finely Ground Limestone

on Cement Hydration. Cement and Concrete Composites, Vol. 21, No. 2, pp. 99–105.

[33]. Chowaniec, O. (2012). Limestone Addition in Cement, Doctoral Thesis, École

Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.

[34]. Yang, C.C., and Chiang, C.T. (2005). On the Relationship Between Pore Structure

and Charge Passed from RCPT in Mineral-free Cement-based Materials, Materials

Chemistry and Physics, Vol. 93, No. 1, pp. 202–207.

[35]. Tikkanen, J., Cwirzen, A., and Penttala, V. (2011). Mineral Powder Concrete –

Effects of Powder Content on Concrete Properties, Magazine of Concrete Research,

Vol. 63, No.12, pp. 893–903.

51

Chapter 3 - Hydration Kinetics and Compressive Strength of Steam-Cured Cement Pastes and Mortars Containing

Limestone Filler

Abstract

This chapter aims to evaluate the influence of limestone filler content and fineness on the

hydration kinetics and the compressive strength of steam cured cement mortars and pastes.

Experimental variables were cement fineness, limestone filler content, limestone filler

fineness and steam curing duration. Mortar and paste specimens were steam cured at 55°C

for 12 and 16 hours. The hydration kinetics were evaluated using the heat of hydration and

thermal analysis. The heat of hydration was measured using Isothermal Calorimetry. The

calcium hydroxide (Ca(OH)2) content, calcium carbonate (CaCO3) content and degree of

hydration were measured using thermal gravimetric analysis and differential thermal

analysis. The compressive strength of mortars was evaluated at 12 and 16 hours, and at 3,

7 and 28 days. The results showed an increase in the heat of hydration, Ca(OH)2 content

and early age strength (i.e., at 12 and 16 hours) with the addition of limestone filler. The

results also revealed that the influence of limestone filler on hydration kinetics and strength

was influenced by the finenesses of the limestone filler and the cement. In general, mix

designs containing limestone filler showed improved early age hydration and strength in

mix designs made with higher cement fineness. Increasing limestone filler fineness or

cement fineness reduced the negative impact on the mechanical properties of mortars due

to cement dilution.

Keywords: Limestone filler, Cement fineness, Thermal analysis, Heat of hydration,

Compressive strength

52

3.1. Introduction

Limestone filler (LF) is a fine powder produced from grinding calcitic limestone rocks

obtained from quarries. LF can be utilized as a replacement of cement clinker to reduce

energy consumption and reduce CO2 emission associated with the cement production [1,2].

The effects of LF on the hydration kinetics and compressive strength when concrete is

cured at ambient temperature have been the focus of many research efforts [3,4,5]. The

outcomes indicate that LF influences the cement system through physical and chemical

effects. The physical effects are modification of particle size distribution, heterogeneous

nucleation and dilution [6,7]. The chemical effect is the reaction of LF with monosulfate

and calcium aluminate to form calcium monocarboaluminate.

LF particles fill the voids between coarser cement particles and thus increase the density

and reduce the total pore volume of the cement system [8]. The surface of LF particles acts

as nucleation sites for the precipitation of the hydration products [9]. The nucleation sites

provided by LF reduce the energy barrier and allow the hydration products to precipitate

faster from the pore solution; this increases the rate of hydration reactions and early age

strength gain, which is described as the acceleration effect [10,11,12].

Unlike modification of particle size distribution or heterogeneous nucleation, dilution can

have adverse effects on the strength and durability of concrete. Dilution occurs as a result

of replacing reactive material such as cement by a nonreactive or relatively less reactive

material such as LF [9]. The adverse effect of dilution is mainly due to the reduction in the

hydration products. When LF is used to replace more than 5% of the cement, the dilution

effect masks the other effects (i.e., modification of particle size distribution, heterogeneous

nucleation and chemical reaction). Dilution decreases the compressive strength of concrete

at all ages. However, it is mainly observed at later age (i.e., after 3 days) [13]. This is due

to the heterogeneous nucleation effect of LF that compensates for the dilution effect at

early age (i.e., before 3 days).

There is a general agreement in the literature regarding the reactivity of limestone (CaCO3)

with the monosulfate ((CaO)3(Al2O3)·CaSO4·12H2O) or calcium aluminate hydrate

((CaO)3(Al2O3)·6H2O) to form calcium monocarboaluminate (3CaO·

Al2O3·CaCO3·11H2O), as presented in Equations 3.1 and 3.2 [14,15,16]. However, there

53

is disagreement on the amount of the total available LF in the system that can be consumed

in these reactions [17].


(CaO)3(Al2O3)·3CaSO4·32H2O Eq. 3.1

(CaO)3(Al2O3)·6H2O + CaCO3 + 5H2O → (CaO)3(Al2O3)·CaCO3·11H2O Eq. 3.2

These effects of LF on the hydration rate and the early age strength gain are agreed upon

in the literature for curing at ambient temperature (i.e., 23°C) [18,19,20,21]. This includes

blended or interground limestone at replacement levels up to 5% in CSA type GU cement

and at replacement levels up to 15% in Portland limestone cement (PLC). However, there

is limited data in the literature on how limestone influences the hydration rate and early

age strength gain when concrete is steam cured [18,19]. The hydration reactions under

steam curing conditions are accelerated due to the increase in the temperature. However,

during the steam curing, the chemical reaction of LF is reduced due to that fact that the

solubility of LF decreases with the increase in the temperature [22]. Therefore, the

influence of LF under steam curing conditions is expected to be different compared to

moist curing at ambient temperature.

The study of the interplay between cement type, LF content and LF fineness of steam cured

cement-based material is warranted. The impact of lower solubility of LF and rapid

hydration rate on the behavior of LF under steam curing conditions is important to

understand. This chapter aims to evaluate the influence of LF content and fineness on steam

cured cement paste and mortar. This was achieved by evaluating the effects of LF content

and fineness on the hydration kinetics and the compressive strength of steam cured cement

mortars and pastes. In addition, the reactivity of LF under steam curing conditions was

assessed. Two types of cement were selected, namely CSA general use (Type GU) cement

and high early strength (Type HE) cement to represent the common cements used in the

precast/prestressed concrete applications. Three LFs with different sizes (17µm, 12µm and

3µm) were selected to cover a wide range of particle size distribution. The percentage of

blended LF was 0, 5, 10 and 15% to evaluate the influence of LF at different cement

replacement levels. The maximum steam curing temperature was set at 55°C to prevent

any alteration in the microstructure of cement mortars and pastes due to delayed ettringite

formation [23]. The heat of hydration, phase composition using Thermal gravimetric

54

analysis and differential thermal analysis (TG/DTA) and compressive strength were

investigated. A multiple linear regression analysis was conducted to identify the primary

variables that control the hydration kinetics and the compressive strength evolution from

12 hours to 28 days.


3.2.1. Materials and Mix Design

Two types of cement were used, CSA Type general use (GU) and CSA Type high early

strength (HE) cements, both supplied by Holcim Canada. The GU cement had a Blaine

fineness of 392 m2/kg and the HE cement had a Blaine fineness of 514 m2/kg. The GU

cement had 2.5% interground limestone and the HE cement had 3.5% interground

limestone. Three LFs with different nominal particle sizes (17µm, 12µm and 3µm which

correspond to Blaine fineness of 475, 380 and 1125 m2/kg, respectively) were supplied by

Omya, Canada. The chemical and physical properties of cements, and the LF are presented

in Tables 3.1 and 3.2, respectively. The fine aggregate was natural sand with a specific

gravity of 2.72 and a fineness modulus of 2.84. The fine aggregate was supplied by

Dufferin Aggregates.

Table 3.1: Chemical and Physical Properties of Cements

Chemical and Physical Properties Cement Type

GU HE

SiO2 (%) 19.25 19.10

Al2O3 (%) 5.33 5.18

Fe2O3 (%) 2.41 2.35

CaO (%) 62.78 61.60

MgO (%) 2.36 2.35

SO3 (%) 4.01 4.26

Na2Oeq (%) 0.99 1.01

C3S (%) 58.55 55.15

C3A (%) 10.04 9.75

C4AF (%) 7.34 7.14

C2S (%) 11.03 13.18

LOI at 1150 °C (%) 2.27 2.10

Blaine (m2/kg) 392 514

Limestone Content (CaCO3) 2.50 3.50

55

Table 3.2: Chemical and Physical Properties of LF

Chemical and Physical Properties LF Size

17µm 12µm 3µm

LOI at 1050°C (%) 42.8 42.3 42.4

CaCO3 (%) 95.0 96.0 96.0

MgCO3 (%) 2.0 2.0 2.0

% Retained on 44μm mesh 15.000 0.500 0.003

Moisture Loss at 110°C (%) 0.03 0.05 0.08

Blaine (m2/kg) 475 380 1125

Specific Gravity 2.7 2.7 2.7

Twenty mix designs were examined in this chapter. The mix proportions are presented in

Table 3.3. For each mix design, mortars and pastes were prepared. The mortar was used

for the cube compressive strength evaluation and the corresponding paste was used to

measure the heat of hydration, calcium hydroxide (Ca(OH)2) content, calcium carbonate

(CaCO3) content and the degree of hydration. The water-to-cement ratio and sand-to-

cement ratio were kept constant at 0.37 and 2, respectively. Cement, sand and LF (when

used) were blended initially for 2 minutes in a 10-litre mortar mixer. After the addition of

water, the materials were mixed for 4 minutes. Similar mixing procedures were followed

for the corresponding paste mixes. For each mix design, 15 mortar cubes (50 mm × 50 mm

× 50 mm) were prepared for the compressive strength testing and paste was prepared for

the Isothermal Calorimetry and TG/DTA testing.


Steam curing was conducted in a 0.45 m3 environmental chamber manufactured by

Cincinnati Sub-Zero. After mixing, the specimens were cured at 23°C and 98% relative

humidity (RH) for 2 hours (preset period) to ensure that the steam curing was applied after

the initial setting [24]. The maximum holding temperature of steam curing was 55°C with

a RH of 98% which was controlled by a steam generator built into the chamber. The curing

regime is presented in Figure 3.1. After the preset period, the specimens were steam cured

in the following sequence:

i. heating to 55°C in 2 hours (16°C /hour) while maintaining 98%RH

ii. holding the temperature at 55°C while maintaining 98%RH for 10 hours for the

16-hour curing regime or for 6 hours for the 12-hour curing regime

56

iii. cooling to 23°C in 2 hours (16°C /hour) while maintaining 98%RH (in the

chamber)

The temperature of the chamber was controlled to maintain the required internal

temperature of the samples, using Type T thermocouples embedded in the samples at the

centroid. After 12 or 16 hours, all specimens were moist cured in limewater at 23°C until

tested (i.e., 3, 7 and 28 days). Thermal analysis was conducted after 16 hours of steam

curing and after 28 days (16 hours of steam curing followed by moist curing in limewater

until 28 days). The selection of 16 hours for the thermal analysis was to reflect the common

curing regimes used in the precast/prestressed applications in Ontario, Canada.

Table 3.3: Mortar and Paste Mix Details

# Mix ID Cement (%) Blended LF

W/C ratio Content (%) Size (µm)

1 GU 100 GU 0 ---

0.37

2 GU-5-17µm 95 GU 5

17 3 GU-10-17µm 90 GU 10

4 GU-15-17µm 85 GU 15

5 GU -5-12µm 95 GU 5

12 6 GU-10-12µm 90 GU 10

7 GU-15-12µm 85 GU 15

8 GU-5-3µm 95 GU 5

3 9 GU-10-3µm 90 GU 10

10 GU-15-3µm 85 GU 15

11 HE 100 HE 0 ---

12 HE-5-17µm 95 HE 5

17 13 HE-10-17µm 90 HE 10

14 HE-15-17µm 85 HE 15

15 HE-5-12µm 95 HE 5

12 16 HE-10-12µm 90 HE 10

17 HE-15-12µm 85 HE 15

18 HE-5-3µm 95 HE 5

3 19 HE-10-3µm 90 HE 10

20 HE-15-3µm 85 HE 15

57

Figure 3.1: Steam Curing Regimes

3.2.3. Test Methods

Initial Setting Time: The normal consistency and the initial setting time were measured

according to ASTM C187-11 and ASTM C191-08, respectively.

Heat of Hydration: For each mix design, three cement paste samples were tested for the

heat of hydration over a period of 72 hours. The test was conducted at 23°C in accordance

with ASTM C1702-09 Method B. A TAM Air isothermal calorimeter manufactured by

Thermometric was used.

Thermal Analysis: The TG/DTA analysis was conducted to measure the Ca(OH)2, CaCO3

and non-evaporable water contents. For each mix design, there TG/DTA tests were

conducted. Netzsch SA Simultaneous Thermal Analyzer heated to 1145°C at a heating rate

of 10°C/min was used. The degree of hydration was calculated by dividing the mass loss

between 23°C and 550°C by the maximum theoretical non-evaporable water (i.e., 0.23), as

presented in Equation 3.3 [25]. The selection of this temperature range (i.e., 23°C to 550°C)

to calculate the degree of hydration was due to the fact that most of the non-evaporable

water content is lost below 550°C [25]. The percentage of Ca(OH)2 and degree of hydration

was used as a measure to evaluate the hydration products to provide a relative comparison

between mix designs. The reactivity of LF was evaluated by calculating the difference

between the initial and the final CaCO3 content. The initial content of CaCO3 (prior to

mixing) was calculated according to Equation 3.4. The mass loss at approximately 680 to

10

15

20

25

30

35

40

45

50

55

60

0 2 4 6 8 10 12 14 16 18

Tem

per

atu

re (

°C)

Time (hour)

Curing Regime Actual Temperature

12-hour steam curing regime


58

800°C was used to measure the final CaCO3 content as a percentage by weight (wt%) using

stoichiometry, as presented in Equation 3.5 [26]. In Equation 5.5, the blended LF content

was corrected for LF purity. The mass loss at approximately 450 to 500°C was used to

measure the Ca(OH)2 content, as presented in Equation 3.6.

Degree of Hydration = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (23−550°C )

0.23 Eq.3.3


𝑇𝑜𝑡𝑎𝑙 𝑀𝑎𝑠𝑠 (𝑐𝑒𝑚𝑒𝑛𝑡+𝐿𝐹+𝑤𝑎𝑡𝑒𝑟)× 100 Eq.3.4


Molar Mass of CO2 Eq.3.5

Measured Ca(OH)2 Content (wt%) = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (450 − 500°C ) ×Molar Mass of Ca(OH)2

Molar Mass of H2O

Eq.3.6

The difference between the initial and the final CaCO3 content was assumed to be the

portion of LF that was consumed in the chemical reaction with monosulfate and aluminate

phases in the hydrated cement system to form calcium monocarboaluminate. To accurately

measure the non-evaporable water, the specimens were freeze-dried. The freeze-drying

process consisted of two steps. The first step was freezing the samples using liquid nitrogen

to stop the hydration. The second step was placing the samples in sealed desiccator under

vacuum at -10°C. The samples were freeze-dried until a constant mass (less than 0.1%

change in 24-hour period) was achieved

Compressive Strength: The cube compressive strength of mortar samples was measured in

accordance with ASTM C109-12. For each mortar mix design, three cubes were tested at

12 hours, 16 hours and at 3, 7 and 28 days.


3.3.1. Influence of Limestone Filler Size and Content

3.3.1.1. Initial Setting Time

The normal consistency and the initial setting time were measured for mixtures containing

0% and 15% LF, and are presented in Table 3.4. The addition of LF decreases the initial

setting time for both GU and HE cement pastes. Similar percentage reduction in the initial

setting time was observed in pastes made of GU and HE cement when LF of 17µm or 12µm

59

was used, as presented in Table 3.4. Paste made of GU cement and 3µm LF showed a

relatively higher reduction (14.3%) in the initial setting time compared to paste made with

HE cement and 3µm LF (10.6%). In general, the reduction in LF size from 17µm to 12µm

did not cause any significant change in the initial setting time for pastes made with GU or

HE cement. The increase in the hydration rate and the reduction in the initial setting time

in the presence of LF can be attributed to the increase in nucleation surface area particularly

with 3µm LF size [10,27].

Table 3.4: Normal Consistency and Initial Setting Time

MIX ID Normal

Consistency Initial Setting (mins.)

Reduction in Initial

Setting time (%)*

GU 0.270 98 ---

GU-15-17µm 0.295 94 4.0

GU-15-12µm 0.295 92 6.1

GU-15-3µm 0.300 84 14.3

HE 0.310 94 ---

HE-15-17µm 0.330 90 4.3

HE-15-12µm 0.330 89 5.3

HE-15-3µm 0.335 80 10.6

*Compared to control (GU or HE) mixtures

3.3.1.2. Heat of Hydration

The effect of LF content and size on the heat of hydration of GU and HE mixtures is

presented in Figure 3.2. Figure 3.2a presents the effect of 17µm LF content on the heat of

hydration of GU and HE cement mixtures. Figures 3.2b and 3.2c present the effect of 12µm

and 3µm LF content, respectively. The heat of hydration curves presented in Figure 3.2 are

used to calculate the total energy released presented in Figure 3.3. The presence of LF

increased the heat of hydration regardless of LF content or size compared to pastes made

without LF. The effect of LF was more pronounced in HE mixtures compared to

counterpart GU cement mixtures. It was also observed that the increase in LF content from

5% to 10% to 15% and decrease in LF size from 17µm to 12µm to 3µm increased the heat

of hydration. To further explain these trends, the values of the hydration peak and the total

energy released for the first 20 hours of hydration were compared for each mixture and are

shown in Figures 3.4 and 3.5. The first 20 hours of hydration was selected as a base for

comparison as most of the hydration heat is released during this period.

60

Figure 3.2: Effect of LF on the Heat of Hydration for Pastes with a) 17µm LF, b) 12µm

LF and c) 3 µm LF

0

1

2

3

4

5

6

7

0 5 10 15 20

Po

wer

(m

W/g

)

Time (hour)

GU GU-5-17µm GU-10-17µm GU-15-17µm

HE HE-5-17µm HE-10-17µm HE-15-17µma)

0

1

2

3

4

5

6

7

0 5 10 15 20

Po

wer

(m

W/g

)

Time (hour)


HE HE-5-12µm HE-10-12µm HE-15-12µmb)

0

1

2

3

4

5

6

7

0 5 10 15 20

Po

wer

(m

W/g

)

Time (hour)


HE HE-5-3µm HE-10-3µm HE-15-3µmc)

61

Figure 3.3: Effect of LF on the Total Energy Released for Pastes with a) 17µm LF, b)

12µm LF and c) 3 µm LF

0

50

100

150

200

250

0 5 10 15 20

Ener

gy (

J/g)

Time (hour)


HE HE-5-17µm HE-10-17µm HE-15-17µma)

0

50

100

150

200

250

0 5 10 15 20

Ener

gy (

J/g)

Time (hour)


HE HE-5-12µm HE-10-12µm HE-15-12µmb)

0

50

100

150

200

250

0 5 10 15 20

Ener

gy (

J/g)

Time (hour)

GU GU-5-3µm GU-10-3µm GU-15-3µmHE HE-5-3µm HE-10-3µm HE-15-3µm

c)

62

a) Hydration Peak

The influence of LF size and content on the hydration peak is presented in Figure 3.4. Each

point in the curve is the average of three tests and the corresponding coefficient of variation

was less than 3% for all mixes (please refer to Section A.6 in Appendix A for the raw data

and the statistical analysis). GU and HE mixes can be compared to the horizontal line

representing the control mixture (i.e., 100% GU and 100% HE). In all pastes made with

GU and HE cement, the maximum peak increased and occurred sooner with higher LF

content and smaller LF size compared to the corresponding control mix (i.e., 100% GU

and 100% HE). This is due to the acceleration effect of LF and agrees with the observations

reported in the literature [28,29].

Figure 3.4: Effect of LF Content and Size on the Hydration Peak

As shown in Figure 3.4, for paste made with GU cement and 5% LF, the increase in the

hydration peak was approximately 4% irrespective of LF size compared to the control mix

(i.e., 100% GU). Pastes made with 17µm and 12µm LF showed approximately similar

hydration peak regardless of LF content. However, LF content increased the hydration peak

in pastes made of 3µm LF. This is due to the greater surface area of 3µm compared to

3.5

4.0

4.5

5.0

5.5

6.0

6.5

17µm 12µm 3µm

Hyd

rati

on P

ow

er (

mW

/g)

LF Size

GU-5%LF GU-10%LF GU-15%LF

HE-5%LF HE-10%LF HE-15%LF

15%LF

10%LF

5%LF

15%LF

5%LF

10%LF

HE

GU

100%HE

100%GU

63

17µm and 12µm LF, which magnifies the acceleration effect of LF on the hydration

process. In pastes made of HE cement, LF of 3µm showed the highest hydration peak

followed by 12µm and 17µm LF. The increase in LF content increased the hydration peak

for all LF sizes. This indicates that the effect of LF on cement hydration can be enhanced

by the increase in cement fineness.

Figure 3.2 reveals that the hydration peaks in pastes made with GU cement were relatively

flat and extended to approximately 3.5 hours in contrast to the sharper peaks observed in

pastes made with HE cement. Second hydration peaks following sulfate depletion point

were more pronounced in GU and HE pastes made with 12μm and 3μm compared to pastes

made with 17μm as shown in Figure 3.2. This could be due to the acceleration in the

hydration reactions including the reaction of C3A and gypsum causing sooner sulfate

depletion point. Figure 3.4 reveals that pastes made with HE cement showed a greater

percentage increase in the hydration peak when LF was added compared to counterpart

pastes made with GU cement.

b) Total Energy Released

The total energy released from the time of water addition to 20 hours was measured for

each mix design and compared to the control mix without LF, as presented in Figure 3.5.

Each point in the curve is the average of three tests and the corresponding coefficient of

variation was less than 2% for all mixes (please refer to Section A.6 in Appendix A for the

raw data and the statistical analysis). The total energy released was calculated as the area

under the power-time curve presented in Figure 3.2. In all pastes, the total energy released

increased with higher LF content and smaller LF size compared to the corresponding

control mix (i.e., 100% GU and 100% HE).

Replacing GU or HE cement with LF increased the total energy released from the system

during the first 20 hours of hydration, which agrees with the observations obtained from

the literature [8]. The increase in the total energy released with LF is caused by the

acceleration in the hydration reactions [30]. The formation of calcium monocarboaluminate

that fills the pores between cement particles could also be a contributing factor [31,32].

As would be expected, pastes made of HE cement showed greater total heat released

compared to pastes made of GU cement. However, blending GU cement with 3µm LF

significantly increase the total heat released. The total heat released of this mix was greater

64

than the total heat released from paste made of 100% HE cement. This shows the important

role of LF fineness in enhancing the hydration rate of coarser cement (i.e., GU cement).

The total energy released after 20 hours of hydration for all pastes made with GU and HE

cements with and without LF ranged from 185 to 221 J/g. This range was reduced with

time as the total energy released after 72 hours of hydration for all pastes made with GU

and HE cements with and without LF ranged from 249 to 269 J/g. This is expected as pastes

made with finer cement (i.e., HE cement) or fine fillers (i.e., LF) showed higher early heat

of hydration than paste made with 100% GU. After approximately 13 hours, the heat of

hydration of pastes made with finer cement (i.e., HE cement) or fine fillers (i.e., LF) was

lower than the paste made with 100% GU, as presented in Figure 3.2.

Figure 3.5: Effect of LF Content and Size on the Total Energy Released after 20 Hours

3.3.1.3. Thermal Analysis

a) Ca(OH)2 Content

Figures 3.6 and 3.7 present the measured Ca(OH)2 content for pastes made with GU and

HE cement, respectively. Each point in the curve is the average of three tests and the

corresponding coefficient of variation was less than 3% for all mixes (please refer to

180

185

190

195

200

205

210

215

220

225

17µm 12µm 3µmTo

tal

Ener

gy R

elea

sed

aft

er 2

0 H

ours

(J

/g)

LF Size

GU-5%LF GU-10%LF GU-15%LF

HE-5%LF HE-10%LF HE-15%LF

15%LF

10%LF

5%LF

15%LF

5%LF10%LF

HE

GU

100% HE

100% GU

65

Section A.6 in Appendix A for the raw data and the statistical analysis). At 16 hours,

Increasing the content of LF increases the Ca(OH)2 content regardless of LF size. The

increase in Ca(OH)2 content can be explained by the increased heat of hydration in the

presence of LF, which increases the hydration products including Ca(OH)2.

Figure 3.6: Effect of LF Content and Size on Ca(OH)2 Content of GU Cement Paste

Figure 6 shows that the increase in LF content up to 10% increased the Ca(OH)2 content

in pastes made of GU cement at 16 hours compared to the control mix (i.e., 100% GU). No

increase in Ca(OH)2 content was observed when the LF content increased to 15%. This is

due to the dilution effect of LF, which was more pronounced at 28 days compared to 16

hours. At 28 days, no effect of LF was observed on Ca(OH)2 content up to 10% replacement

level. Increasing LF content from 10% to 15% caused a reduction in Ca(OH)2 content due

to the dilution effect. For pastes made of HE cement, the addition of 5% LF increased the

Ca(OH)2 content, as presented in Figure 7. Further increase in LF did not cause any

additional increase in Ca(OH)2 content. The dilution effect of LF was more pronounced in

pastes made of GU cement compared to HE cement.

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

5 10 15

Ca(

OH

) 2(%

)

LF Content (%)

GU-17µm GU-12µm GU-3µm

28 Days

16 Hours

100% GU

100% GU

66

.

Figure 3.7: Effect of LF Content and Size on Ca(OH)2 Content of HE Cement Paste

b) CaCO3 Content

Figures 3.8 and 3.9 present the effect of LF size and content on the reactivity of LF (the

difference between the initial and the final CaCO3 content) in pastes made with GU and

HE cement, respectively. Each column in the figures is the average of three tests and the

corresponding standard deviation was less than 0.19 wt% for all mixes (please refer to

Section A.6 in Appendix A for the raw data and the statistical analysis). The initial and

final CaCO3 calculations were made based on Equations 3.4 and 3.5, respectively. The

following is a calculation example for mix HE-15-3 at 28 days:

Initial CaCO3 Content (wt%) = 𝑀𝑎𝑠𝑠 𝑜𝑓 𝐿𝐹 (𝑏𝑙𝑒𝑛𝑑𝑒𝑑+𝑖𝑛𝑡𝑒𝑟𝑔𝑟𝑜𝑢𝑛𝑑)

𝑇𝑜𝑡𝑎𝑙 𝑀𝑎𝑠𝑠 (𝑐𝑒𝑚𝑒𝑛𝑡+𝐿𝐹+𝑤𝑎𝑡𝑒𝑟)× 100

= 148×0.96+0.035×987

(987+148+365)× 100 = 11.77 wt%


Molar Mass of CO2

= 4.28%×100.09

44.01 = 9.73 wt%

Reacted LF (wt%) = 11.77 – 9.73 = 2.03 wt%

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

5 10 15

Ca(

OH

) 2(%

)

LF Content (%)

HE-17µm HE-12µm HE-3µm

28 Days

16 Hours

100% HE

100% HE

67

Reacted LF as Percentage of Total Available LF (%) = 2.03

11.77× 100= 17.3%

From Figures 3.8 and 3.9, it was observed that the reactivity of LF increases with higher

LF content and smaller LF size, which agrees with the literature [18,19]. However, the

increase in the cement fineness increases the rate of LF reaction. This can be observed in

Figures 3.8a and 3.9a as the percentage by weight of reacted LF was higher in HE pastes

compared to counterpart pastes made with GU cement at 16 hours. In addition, the

percentage of reacted LF in GU pastes at 16 hours was less than 20% of the reacted LF of

the same pastes at 28 days. This could be due to the decrease in LF solubility with the

increase in temperature (i.e., at 16 hours, the cement pastes were under steam curing

conditions while at 28 days, the pastes were at 23°C for approximately 27 days after steam

curing) [33]. On the other hand, in pastes made with HE cement and LF, the percentage of

reacted LF at 16 hours compared to 28 days was 14% in 17µm, 37% in 12µm and 58% in

3µm. This indicates that the cement fineness plays an important role in the rate of LF

reaction under steam curing conditions.

Figure 3.8: Effect of LF Content and Size on CaCO3 Content of GU Cement Paste

a)16 hours, b) 28 days

0.0

0.5

1.0

1.5

2.0

2.5

0 5 10 15

Rea

cted

LF

(w

t%)

Blended LF Content (%)

GU GU-17µm GU-12µm GU-3µma)

0.0

0.5

1.0

1.5

2.0

2.5

0 5 10 15

Rea

cted

LF

(w

t%)


GU GU-17µm GU-12µm GU-3µmb)

68

Figure 3.9: Effect of LF Content and Size on CaCO3Content of HE Cement Paste a) 16

hours, b) 28 days

The percentage by weight of the reacted LF for each mix was converted to the reacted LF

as a percentage of the total available LF in the system, as presented in Table 3.5. At 16

hours, the percentage of reacted LF to the total available LF was limited to 4.2% in GU

pastes and 11.5% in HE pastes. At 28 days, the percentage of reacted LF to the total

available LF ranged from 5.0% to 23.4% in pastes made with GU cement and 9.5% to

34.0% in pastes made with HE cement. It is important to note that the results of reacted LF

as a percentage of the total available LF should be interpreted with caution as it reduces

with the increase in the total LF content in the system. For example, for pastes made with

HE cement and 3µm LF, at 28 days, the reactivity of LF increased from 1.43 wt% to 1.60

wt% to 2.03 wt% when the LF content increased from 5% to 10% to 15%, respectively.

However, the reacted LF as a percentage of the total available LF in the system was reduced

from 24.4% to 18.0% to 17.3% when the LF content increased from 5% to 10% to 15%,

respectively. This is due to the fact that increasing LF content will increase the initial

CaCO3 content and thus the reacted LF content is divided by a larger number. Therefore,

0.0

0.5

1.0

1.5

2.0

2.5

0 5 10 15

Rea

cted

LF

(w

t%)


HE HE-17µm HE-12µm HE-3µma)

0.0

0.5

1.0

1.5

2.0

2.5

0 5 10 15

Rea

cted

LF

(w

t%)


HE HE-17µm HE-12µm HE-3µmd)

69

the reactivity of LF as a percentage of the total available LF in the system should only be

used when comparing mixes with similar LF content.

Table 3.5: Reactivity of LF

# Mix ID

LF Reactivity

(wt%)

Reacted LF as Percentage of Total

Available LF in the System (%)

16 hours 28 days 16 hours 28 days

1 GU 0.00 0.14 0.0 7.8

2 GU-5-17µm 0.01 0.40 0.1 7.7

3 GU-10-17µm 0.07 1.19 0.8 14.3

4 GU-15-17µm 0.09 1.56 0.8 14.0

5 GU -5-12µm 0.01 0.26 0.1 5.0

6 GU-10-12µm 0.10 1.28 1.2 15.4

7 GU-15-12µm 0.14 1.18 1.2 10.5

8 GU-5-3µm 0.03 0.31 0.6 5.9

9 GU-10-3µm 0.17 1.94 2.0 23.4

10 GU-15-3µm 0.48 2.27 4.2 20.3

11 HE 0.05 0.96 2.1 34.0

12 HE-5-17µm 0.09 1.45 1.5 24.8

13 HE-10-17µm 0.31 1.12 3.4 12.6

14 HE-15-17µm 0.12 1.12 1.0 9.5

15 HE-5-12µm 0.34 1.52 5.7 26.0

16 HE-10-12µm 0.74 1.38 8.3 15.4

17 HE-15-12µm 0.60 1.64 5.1 14.0

18 HE-5-3µm 0.65 1.43 11.2 24.4

19 HE-10-3µm 0.94 1.60 10.6 18.0

20 HE-15-3µm 1.35 2.03 11.5 17.3

The LF reactivity results at 28 days presented in Figures 3.8 and 3.9 and Table 3.5 were in

agreement with other research work done under moist curing conditions where the reacted

LF as a percentage of the total available LF ranged from 11-32% at 28 days [13,34,35]. At

16 hours, where the samples have been exposed to high temperature (i.e., 55°C), the

reactivity of LF was limited due to the fact that the solubility of CaCO3 reduces with the

increase in temperature. It is expected that most of the LF chemical reaction will take place

after the end of steam curing when the temperature drops to ambient temperature (i.e.,

23°C).

70

c) Degree of Hydration

The results of the degree of hydration are presented in Figures 3.10 and 3.11. Each point

in the curve is the average of three tests and the corresponding coefficient of variation was

equal or less than 4% for all mixes (please refer to Section A.6 in Appendix A for the raw

data and the statistical analysis). For pastes made with HE cement, it is apparent that the

size of LF has a greater influence on the degree of hydration than LF content. However, in

pastes made with GU cement, the LF size and content had a similar effect on the degree of

hydration.

Based on the thermal analysis, LF had a greater impact on the Ca(OH)2 content, CaCO3

content and the degree of hydration in pastes made of HE cement compared to counterpart

pastes made of GU cement. This agrees with the results of the heat of hydration as pastes

made with HE cement showed a higher increase in hydration peak and total energy released

when LF was added compared to counterpart pastes made of GU cement.

Figure 3.10: Effect of LF Content and Size on the Degree of Hydration of Pastes at 16

Hours

0.60

0.61

0.62

0.63

0.64

0.65

0.66

0.67

0.68

0.69

0.70

5 10 15

Deg

ree

of

Hyd

rati

on

LF Content (%)

GU-17μm GU-12μm GU-3μm

HE-17μm HE-12μm HE-3μm

100% HE

100% GU

71

Figure 3.11: Effect of LF Content and Size on the Degree of Hydration of Pastes at 28

Days

3.3.1.4. Cube Compressive Strength

The results of the compressive strength testing are presented in Figures 3.12 to 3.14. Figure

3.12 presents the compressive strength of mortars made with 5% LF. Figures 3.13 and 3.14

present the compressive strength of mortars made with 10% and 15% LF, respectively.

Each compressive strength result is an average of three mortar cubes and the corresponding

coefficient of variation was less than 6% for all mixes (please refer to Section A.6 in

Appendix A for the raw data and the statistical analysis). Figures 3.12 to 3.14 reveals that

LF improves the compressive strength at 12 and 16 hours for HE cement mortars while no

effect of LF was observed with GU cement mortars compared to the corresponding control

mixes (i.e., 100% GU and 100% HE). However, at 3, 7 and 28 days, the effect of LF on

the compressive strength was different when comparing mortars made with GU to those

with HE cement. For GU cement mortars, LF yields a reduction in the compressive strength

after 7 days. On the contrary, the compressive strength of HE cement mortars increased

with the addition of LF at all ages (i.e., at 12 hours and 16 hours and at 3, 7 and 28 days).

0.80

0.81

0.82

0.83

0.84

0.85

0.86

0.87

0.88

0.89

0.90

5 10 15

Deg

ree

of

Hyd

rati

on

LF Content (%)

GU-17μm GU-12μm GU-3μm

HE-17μm HE-12μm HE-3μm

100% HE

100% GU

72

Figure 3.12: Effect of 5% LF on Cement Mortar Compressive Strength


30

35

40

45

50

55

60

65

70

0.1 1 10 100

Cub

e S

tren

gth

(M

Pa)

Age (Days)


HE HE-5-17µm HE-5-12µm HE-5-3µm

12 hrs. 16 hrs.

3 7 28

30

35

40

45

50

55

60

65

70

0.1 1 10 100

Cub

e S

tren

gth

(M

Pa)

Age (Days)



12 hrs. 16 hrs.

3 7 28

73


For mortars made with GU cement, the effect of LF at 12 and 16 hours was less pronounced

compared to mortars made with HE cement. In general, no significant improvement in the

compressive strength was observed at 12 and 16 hours when LF was used with GU cement.

However, at later ages (i.e., 3, 7 and 28 days) the strength of mortars made with LF was

slightly lower (3 to 4%) than the control mix (i.e., 100% GU). The decrease in compressive

strength was greater in mortars made with higher content of LF.

Replacing 5% of HE cement did not cause any significant effect on the compressive

strength of mortar from 12 hours to 28 days, as presented in Figure 3.12. When the LF

content increased from 5% to 10%, the compressive strength of mortar was slightly

increased at all ages compared to the control mix (i.e., 100% HE). Greater compressive

strength was achieved when LF content increased from 10% to 15% compared to the

control mix (i.e., 100% HE). The effect of LF size was greater when LF content was 15%

compared to 5% and 10% LF content. The effect of LF on the compressive strength of

mortars made with HE cement was greater than in mortars made with GU cement. This

agrees with the heat of hydration and thermal analysis results. At 12 and 16 hours, the

improvement in the compressive strength of mortars made with LF can be attributed to the

30

35

40

45

50

55

60

65

70

0.1 1 10 100

Cub

e S

tren

gth

(M

Pa)

Age (Days)



12 hrs. 16 hrs.

3 7 28

74

acceleration of hydration and early production of monocarboaluminate especially in mix

designs made with HE cement.

3.3.2. Influence of Cement Fineness

The increase in cement fineness from 392 m2/kg in GU cement to 514 m2/kg in HE cement

decreased the initial setting time by 4%, as presented in Table 3.4. The hydration peak

values were approximately 40% higher in HE cement pastes made with and without LF

compared to counterpart pastes made with GU cement, as presented in Figure 3.4. The

increase in the cement fineness increases the surface area which in return increases the

hydration rate and thus reduces the initial setting time.

From Figures 3.6 and 3.7 it was observed that the Ca(OH)2 content at 16 hours was

approximately 3% higher in HE cement pastes made with or without LF compared to

counterpart pastes made with GU cement. At 28 days, the content of Ca(OH)2 was 5%

higher in HE cement pastes compared to pastes made with GU cement. Similar observation

was obtained from the degree of hydration results. This indicates that the increase in the

cement fineness can minimize the dilution effect at later age (i.e., 3 days to 28 days).

From Figures 3.8 and 3.9, it was observed that the reactivity of LF was faster in pastes

made with HE cement compared to counterpart pastes made with GU cement. HE pastes

showed greater LF reactivity compared to GU pastes at 16 hours. At 28 days, pastes made

of HE and GU cements showed similar LF reactivity. This indicates that the increase in

cement fineness can accelerate the chemical reaction of LF. Finer cement causes the sulfate

depletion point to occur sooner as shown in Figure 3.2. This allows the LF reaction to start

sooner as LF reaction occurs after the consumption of the initial calcium sulfate in the

system [14]. Comparing HE to GU pastes reveals that the presence of LF did not have any

influence on the effect of cement fineness on the initial setting time, heat of hydration,

Ca(OH)2 or the degree of hydration.

From Figures 3.12 to 3.14, it was observed that the average increase in the mortar

compressive strength at 12 and 16 hours with the use of LF was 24% greater in HE mortars

compared to GU mortars. However, this increase in the compressive strength of HE mortars

compared to GU cement mortars diminished with time (18%, 14% and 9% at 3, 7 and 28

days, respectively), which agrees with the findings of other studies [36,37,38].

75

3.3.3. Influence of Steam Curing Duration

For cement mortars made with GU cement, the compressive strength after 12 hours and 16

hours of steam curing was approximately 59% and 65% of the 28-day compressive

strength, respectively, as presented in Figures 3.12 to 3.14. For HE mortars, the

compressive strength after 12 hours and 16 hours of steam curing was 66% and 72% of the

28-day compressive strength, respectively, as presented in Figures 3.12 to 3.14. This

indicates that a significant portion of the 28-day strength was achieved after 12 hours of

steam curing and only an additional 6% of the 28-day strength was achieved when the

steam curing duration was extended from 12 hours to 16 hours.

3.3.4. Influence of Reacted Limestone Filler

To study the influence of LF reactivity, Figure 3.15 shows the relationship between the

total heat released and compressive strength measurements at 16 hours and the percentage

of reacted LF (wt%) at 16 hours. Figure 3.15 reveals that the increase in the total heat

released and the increase in the percentage of reacted LF at 16 hours increased the

compressive strength. This is due to the acceleration of the hydration process in the

presence of LF, which allows LF to react sooner after the sulfate depletion point and form

monocarboaluminate that fills the voids and increases the compressive strength.

The reactivity of LF at 16 hours plotted against the Ca(OH)2 content and the degree of

hydration measurements at 16 hours is presented in Figure 3.16. Each point in the figure is

the average value of three tests (please refer to Figure A.3 in Appendix A which presents

all the raw data). This figure reveals that the Ca(OH)2 content increases with the increase

in the percentage of reacted LF in the system up to 0.4 wt% of reacted LF. Following this

point, any increase in the amount of reacted LF decreased the Ca(OH)2 content. The

reduction in the Ca(OH)2 content was due to the dilution effect. On the other hand, the

degree of hydration increased with the increase in the percentage of reacted LF in the

system. The degree of hydration is expected to increase due to the acceleration in the

hydration process in the presence of LF and the production of monocarboaluminate. By

comparing the two regression curves in Figure 3.16, it can be observed that the increase in

the percentage of reacted LF compensates for the reduction in the Ca(OH)2 content due to

the dilution effect. This explains the increase in the degree of hydration even at a greater

percentage of reacted LF while Ca(OH)2 content was reduced. No correlation could be

76

established for the reactivity of LF (wt%) with the total heat released, compressive strength,

Ca(OH)2 content or the degree of hydration at 28 days.

Figure 3.15: Relationship between LF Reactivity, Cube Compressive Strength and Total

Heat Released and at 16 hours

Figure 3.16: Relationship between LF Reactivity, Ca(OH)2 Content and Degree of

Hydration at 16 hours

0

25

50

75

100

125

150

175

200

225

250

0

5

10

15

20

25

30

35

40

45

50

55

60

65

0.0 0.4 0.8 1.2 1.6

To

tal

Hea

t R

elea

sed

aft

er 1

6 h

rs.

(J/g

)

Cub

e C

om

pre

ssiv

e S

tren

gth

at

16

hrs

. (M

Pa)

LF Reactivity at 16 hrs. (wt%)

Cube Compressive Strength at 16 hrs. Total Heat Released after 16 hrs.

0.54

0.56

0.58

0.60

0.62

0.64

0.66

0.68

11.8

12.0

12.2

12.4

12.6

12.8

13.0

13.2

13.4

13.6

13.8

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Deg

ree

of

Hyd

rati

on a

t 1

6 h

rs.

Ca(

OH

) 2C

onte

nt

at 1

6 h

rs.

(wt%

)

LF Reactivity at 16 hrs. (wt%)

Ca(OH)2 Content at 16 hrs. Degree of Hydration at 16 hrs.

R2 = 0.77

R2 = 0.71

77

3.3.5. Statistical Analysis

A multiple linear regression analysis was conducted and the value of the beta coefficient

for each independent variable (cement fineness, LF content, LF size, steam curing duration

and moist curing duration) was used to evaluate the influence each variable has on the

dependent variable (heat of hydration, reactivity of LF, degree of hydration and

compressive strength) [39]. The multiple linear regression analysis was conducted at a

confidence level of 95%. The data representing an independent variable were normalized.

The highest beta coefficient precedes the most influential independent variable. The results

of the statistical analysis are presented in Tables 3.6 and 3.7. Cement fineness was the most

influential variable on the heat of hydration and compressive strength while moist curing

duration was the most influential variable on LF reactivity and the degree of hydration. LF

content was the second most influential variable on the heat of hydration while LF size was

the second most influential variable on the degree of hydration. The statistical analysis

showed that the hydration kinetics and strength of steam cured cement pastes and mortars

made with LF were greatly influenced by the fineness of the cement.

Table 3.6: Multiple Linear Regression Analysis

Property Prediction Equation R2

Heat of

Hydration

Hydration Peak Value (mW

g)

= 8.53 × C + 0.62 × LFC − 0.22 × LFS − 3.11

0.98

LF Reactivity Reacted LF(wt%) = 2.71 ∙ C + 1.25 ∙ LFC − 0.46 ∙ LFS + 3.31 ∙ Am − 2.45 0.83

Degree of

Hydration DOH = 8.82 × 10−3 ∙ C + 1.38 × 10−3 ∙ LFC − 1.16 × 10−2 ∙ LFS

+0.187 ∙ Am + 0.66 0.99

Early Age

Compressive

Strength (12 and

16 hrs.)

Early Age (12 and 16 hours) Strength (MPa) = 46.35 × C + 0.89 × LFC + 0.14 × LFS + 15.8 × As

− 15.21

0.93

Later Age

Compressive

Strength (3, 7

and 28 days)

Later Age (3, 7 and 28 days) Strength (Mpa)

= 41.78 × C + 0.16 × LFC − 1.91 × LFS + 15.19 × Am + 11.13 0.93

Where:

C: cement fineness coefficient = 𝐵𝑙𝑎𝑖𝑛𝑒 𝐹𝑖𝑛𝑒𝑛𝑒𝑠𝑠 (

𝑚2

𝑘𝑔)

514 (i.e., for GU = 0.81 and HE =1.00)

LFContent: blended LF content coefficient = 𝐿𝐹 𝑐𝑜𝑛𝑡𝑒𝑛𝑡 (%)

15

LFSize : blended LF size coefficient = 𝐿𝐹 𝑠𝑖𝑧𝑒 (µ𝑚)

17

As: steam curing period coefficient = steam curing period (ℎ𝑜𝑢𝑟𝑠)

16

Am: moist curing period coefficient = moist curing period (𝑑𝑎𝑦𝑠)

28

78

Table 3.7: Controlling Variables of Mortars and Pastes Mix Designs

Property Controlling Variables

(1= highest influence , 3= lowest influence) 1 2 3

Heat of Hydration Cement

Fineness LFContent LFSize

LF Reactivity Moist Curing

Duration Cement

Fineness LFContent

Degree of Hydration Moist Curing

Duration LFSize

Cement

Fineness Early Age Compressive

Strength (12 and 16 hours) Cement

Fineness Steam Curing

Duration LFContent

Later Age Compressive

Strength (3, 7 and 28 days) Cement

Fineness Moist Curing

Duration LFSize

3.4. Conclusions


(i) The results of the isothermal calorimetry, thermal analysis and compressive

strength showed an improved early age hydration and compressive strength at 12

and 16 hours with finer limestone filler and cement (i.e., HE cement). This

improvement was more pronounced with greater limestone filler content (i.e., 15%)

and greater fineness (i.e., 3µm limestone filler). Increasing cement fineness in HE

cement compared to GU cement increases the acceleration effect of limestone filler

on the hydration process. The finer cement particles in HE cement allow more

cement to hydrate sooner and thus magnify the acceleration effect of limestone

filler on the hydration process.

(ii) The reactivity of limestone filler was found to be limited to 34% of the total

limestone filler available in the mix and depends mainly on the fineness of

limestone filler and cement fineness. The increase in limestone filler fineness

increased the total reacted limestone filler while the increase in cement fineness

increased the rate of the limestone filler reaction. The reactivity of limestone filler

had an important role in reducing the dilution effect.

(iii) The degree of hydration increased with an increase in cement fineness from 392

m2/kg to 514 m2/kg, at 16 hours. However, increasing cement fineness did not

significantly influence the degree of hydration at 28 days. Moist curing duration

79

and the fineness of limestone filler were the most influential variables on the degree

of hydration.

(iv) At higher limestone filler contents (i.e., 10% and 15%) the dilution effect at later

age (i.e., 3, 7 and 28 days) was reduced by increasing the fineness of the cement

(i.e., using HE cement).

(v) Statistical analysis showed that the hydration kinetics of cement pastes and the

compressive strength of mortars made with limestone filler were greatly influenced

by the fineness of the cement.

3.5. Acknowledgments

This research was supported by the Ministry of Transportation of Ontario. Opinions

expressed in this thesis are those of the authors and may not necessarily reflect the views

and policies of the Ministry of Transportation of Ontario. The authors would like to

acknowledge Holcim Canada for providing the cement, Omya Canada for providing the

limestone and Dufferin Aggregates for providing the fine aggregates.

3.6. References

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Pozzolana and Limestone Blended Cement Concretes Containing Different

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[2] Boubitsas, D. (2004). Replacement of Cement by Limestone Filler: The Effect on

Strength and Chloride Migration in Cement Mortars. Nordic Concrete Research

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[3] Voglis, N., Kakali, G., Chaniotakis, E., and Tsivilis, S. (2005). Portland-limestone

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Self-Compacting Concrete. Cement and Concrete Research, Vol. 35, No. 8, pp.

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Stutzman, P., Tanesi, J., and Weiss, W.J. (2015). Multi-scale Investigation of the

Performance of Limestone in Concrete. Construction and Building Materials, Vol.

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[8] Chen, J.J., Kwan, A.K.H., and Jiang, Y. (2014). Adding Limestone Fines as Cement

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[9] Irassar, E.F. (2009). Sulfate Attack on Cementitious Materials Containing Limestone

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[17] Kakali, G., Tsivilis, S., Aggeli, E., and Bati, M. (2000). Hydration Products of C3A,

C3S and Portland Cement in the Presence of CaCO3. Cement and Concrete Research,

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[19] Hooton, D., Nokken, M., and Thomas, M. (2007). Portland-Limestone Cements:

State of the Art Report and Gap Analysis for CSA A3000. Cement Association of

Canada, SN3053.

[20] Beixing, L., Mingkai, Z., Yanwei, F., Putao, S., and Guoj, K. (2011). Self-

Compacting Concrete-Filled Steel Tubes Prepared from Manufactured Sand with a

High Content of Limestone Fine. Journal of Wuhan University of Technology-

Materials Science Edition, Vol. 26, No. 2, pp. 325–328.




[22] Babuskin, V., Matveev, G., and Mchedlov-Petrosyan, O. (1985). Thermodynamics

of Silicate. 3rd Edition, Berlin, Germany: Springer -Verlag.

[23] Berodier, E., and Scrivener, K. (2014). Understanding the Filler Effect on the

Nucleation and Growth of C-S-H. Journal of the American Ceramic Society, Vol

3773, pp. 3764–3773.


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Prestressed Concrete Applications. PCI Journal, Summer 2012.

[25] Pane, I., and Hansen, W. (2005). Investigation of Blended Cement Hydration by

Isothermal Calorimetry and Thermal Analysis. Cement and Concrete Research, Vol.

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[27] Rahhal, V., Bonavetti, V., Trusilewicz, L., Pedrajas, C., and Talero, R. (2012). Role

of the Filler on Portland Cement Hydration at Early Ages. Construction and Building

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[28] Lothenbach, B., Le Saout, G., Gallucci, E., and Scrivener, K. (2008). Influence of

limestone on the hydration of Portland cements, Cement and Concrete Research, Vol.

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[29] Schutter, G. (2011). Effect of Limestone Filler as Mineral Addition in Self-

Compacting Concrete. 36th Conference on Our World in Concrete and Structures.

August 14–16, Singapore.

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of Inert Materials on Short-Term Hydration. Cement and Concrete Research, Vol.

33, No. 12, pp. 1939–1947.

[31] Shuhua, L., Lihua, L., Meijuan, R., and Zhiyang, G. (2012). Effect of Limestone

Powder on Microstructure and Strength of Ultra-High Performance Cement-Based

Materials. Advanced Science Letters, Vol. 15, No. 1, pp. 475–479.

[32] Heikal, M., El-Didamony, H., and Morsy, M. (2000). Limestone-filled Pozzolanic

Cement. Cement and Concrete Research, Vol. 30, No. 11, pp. 1827–1834.

[33] Coto, B., Martos, C., Pena, J., Rodriguez, R., and Pastor, G. (2012). Effects in the

Solubility of CaCO3: Experimental Study and Model Description. Fluid Phase

Equilibria, Vol. 324, No. 25, pp. 1–7.

[34] Ipavec, A., Gabrovsek, R., Vuk, T., Kaucic, V., Macek, J., and Meden, A. (2011).

Carboaluminate Phases Formation During the Hydration of Calcite-containing

Portland Cement. Journal of the American Ceramic Society, Vol. 94, No. 4, pp. 1238–

1242.

[35] Klemm, W., and Adams, L. (1990). An Investigation of the Formation of

Carboaluminates, Carbonate Additions to Cement. ASTM STP 1064, pp. 60–72.

[36] Bentz, P. (2010). Blending Different Fineness Cements to Engineer the Properties of

Cement-based Materials. Magazine of Concrete Research, Vol. 62, No. 5, pp.:327–

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Study on the Parameters Affecting the Properties of Portland Limestone Cements.

Cement and Concrete Composites, Vol. 21, No. 2, pp. 107–116.

[38] Sarkar, L. (1990). Effect of Blaine Fineness Reversal on Hydration and Strength of

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83

Chapter 4 - Effect of Cement and Limestone Particle Size on the Durability of Steam Cured Self-Consolidating Concrete

Abstract

This chapter describes a laboratory program to investigate the influence of cement and

limestone filler particle size on the hardened properties and durability performance of

steam cured self-consolidating concrete. In addition, the interplay between cement type

and limestone filler particle size was investigated. CSA type GU and HE cements were

used with 5% silica fume. The water-to-cement ratio was 0.34. Limestone filler with two

nominal particle sizes of 17µm and 3µm, which correspond to Blaine finenesses of 475

and 1125 m2/kg, respectively, were used. In addition to plastic concrete properties,

hardened properties including compressive strength, elastic modulus, ultrasonic pulse

velocity and density were measured at 12 and 16 hours and at 3, 7 and 28 days. Durability

performance including rapid chloride permeability testing, sulfate resistance, linear

shrinkage, salt scaling resistance and freeze-thaw resistance were evaluated. The results

showed that limestone filler improved the 12 and 16 hour strength with no influence on

later age strength (3 to 28 days). The linear shrinkage and rapid chloride permeability

decreased with the addition of limestone filler. This reduction was linked to the production

of calcium monocarboaluminate. Limestone filler did not impact the sulfate resistance, salt

scaling resistance or freeze-thaw resistance of concrete.

Keywords: limestone filler, self-consolidating concrete, calcium monocarboaluminate,

compressive strength, durability

84

4.1. Introduction

Self-consolidating concrete (SCC) has been proven to have several benefits for the

construction industry including i) eliminate the need for surface finishing, ii) decrease the

casting time and iii) reduce noise exposure and congestion at the casting place [1,2]. These

advantages are beneficial for precast/prestressed applications where maintaining

production schedule is critical. However, SCC has a higher cost compared to traditional

concrete due to the higher cement content, the use of various chemical admixtures, and the

increased formwork pressure [3,4]. Furthermore, SCC is usually made with a water-to-

cement ratio of 0.32 to 0.36, which increases the portion of the cement that remains

unhydrated. The unhydrated cement acts as an expensive filler [5]. In addition, the volume

of fine and coarse aggregates in SCC is 6% to 10% lower compared to traditional concrete

[1,3,5]. This means that SCC requires 6% to 10% higher paste volume compared to

traditional concrete to coat the aggregates and fill the voids between aggregate particles.

Since cement paste acts as a lubricant for the concrete, coating the aggregates has a direct

impact on concrete workability. Filling the voids between aggregate particles with cement

paste reduces the entrapped air voids and thus improves the strength and durability of the

concrete. The higher paste volume in SCC reduces the volume stability and increases the

risk of cracking [6]. This is due to the fact that the concrete expansion and contraction is

caused only by the cement paste fraction of concrete [6]. Therefore, SCC should be

designed to achieve the required strength with the minimum amount of cement paste to

ensure volume stability.

One approach to address the higher amount of cement and cement paste content in SCC is

by replacing the cement with a filler material such as limestone filler (LF). The filler

material reduces the voids between aggregate particles and thus reduces the required

amount of cement paste. This approach has been proven to reduce the cost as well as the

negative environmental impact of the concrete [7,8,9].

The effect of LF on the durability performance of SCC has been the focus of many research

efforts. Findings have shown that LF can improve the transport properties and volume

stability due to improved packing density and the production of calcium

monocarboaluminate [10,11,12]. However, these studies were conducted under normal

curing conditions (i.e., at 23°C and 90-100% RH) while the information available on the

influence of LF on the durability performance of steam cured SCC is limited. Due to the

85

elevated steam curing temperature, the hydration rate is accelerated. In addition, the

increase in the temperature reduces the solubility of LF [13], which can influence the

interaction between LF and cementing materials and have implications on the hardened

properties of concrete.

LF is often categorized by the LF producers and the construction industry using particle

size [11,14]. The available data in the literature showed that the decrease in LF particle size

increases the heat of hydration and the early age strength gain while reducing the bleeding

and the early age volume change [14,15,16]. These effects can be beneficial to

precast/prestressed applications where high early strength is required. Furthermore, in

precast/prestressed applications, both GU and HE cements are commonly used. Therefore,

understanding the role of particle size of both LF and cement and how they interact and

impact the strength and durability of concrete is critical to ensure high early strength

without impacting long-term durability performance.

The aim of this chapter is to examine the influence of particle size of LF and cement on

plastic properties, hardened properties and durability performance of steam cured SCC.

This will be achieved by evaluating the influence of particle size of LF and cement on the

hydration kinetics, plastic, hardened and transport properties, and durability performance

of steam cured SCC. CSA general use (Type GU) and high early strength (Type HE)

cements were selected to represent the common cements used in the precast/prestressed

applications in Canada. The Blaine fineness of GU and HE cement were 392 and 514

m2/kg, respectively. LF, with two nominal particle sizes of 17µm and 3µm which

correspond to Blaine finenesses of 475 and 1125 m2/kg, respectively, was used. Steam

curing was conducted at a maximum temperature of 55°C to prevent any alteration in the

microstructure of concrete due to delayed ettringite formation [17]. Hydration kinetics and

phase composition of cement pastes were evaluated using the heat of hydration and

Thermal Gravimetric Analysis and Differential Thermal Analysis (TG/DTA). Mortar

strength evolution was measured from 12 hours to 28 days. Plastic properties of SCC

including slump flow, T50, J-ring, visual stability index (VSI), L-box and column

segregation were measured. Hardened properties including compressive strength, elastic

modulus, ultrasonic pulse velocity (UPV) and density were measured at 12 and 16 hours

and at 3, 7 and 28 days. The transport properties were evaluated using rapid chloride

permeability test (RCPT) at 28 days. The durability performance of SCC was evaluated

86

using sulfate resistance, linear shrinkage, salt scaling resistance and freeze-thaw resistance.

A multiple linear regression analysis was conducted to identify the primary variables that

control the hardened and transport properties of concrete mixtures.


4.2.1. Materials

Two types of cements, CSA Type GU and HE with Blaine fineness of 392 and 514 m2/kg,

respectively, were used, which represent the commonly used cements in

precast/prestressed applications. The cements were supplied by Holcim Canada. The

chemical and physical properties of the GU and HE cements are presented in Table 4.1.

The interground limestone content in GU and HE cement was 2.5 and 3.5%, respectively.

The silica fume (SF) used was an undensified powder, from the production of silicon metal,

supplied by SKW Canada. Two LFs were used with nominal particle sizes of 17µm and

3µm which correspond to Blaine fineness of 475 and 1125 m2/kg, respectively. LF was

supplied by Omya Canada. The chemical and the physical properties of LF are presented

in Table 4.2. The fine aggregate was natural sand with a specific gravity of 2.72 and a

fineness modulus of 2.84. The coarse aggregate was crushed limestone with a maximum

size of 13 mm. The coarse aggregate was washed with water before using it in concrete to

eliminate any contamination or fine particles. The sand and coarse aggregate were supplied

by Dufferin Aggregates. Two admixtures supplied by Euclid Chemical Company, Canada

were used; high-range water reducer (HRWR) (Plastol 6400) and air-entraining admixture

(AEA) (Airex-L).

4.2.2. Mix Design

The details for six SCC mix designs are given in Table 4.3 and the corresponding mixture

proportions are presented in Table 4.4. The SCC mixes were designed to achieve a

minimum compressive strength of 44 MPa in 16 hours to represent the current practice in

the precast/prestressed applications in Canada. Due to the high early age strength

requirement, all SCC mixes were designed with 5% SF and w/c of 0.34. The sand-to-total

aggregate ratio (S/A) were kept constant at 0.47. All concrete mixes were designed with

5% fresh air content. The CSA A23.1-14 sets the fresh air content based on the maximum

aggregate size in concrete. For concrete made with a maximum aggregate size of 10 mm,

the required fresh air content is 6 to 9%. Concrete made of aggregate with a maximum

87

aggregate size of 14 to 20 mm requires 5 to 8% fresh air content. Since the maximum

aggregate size used in this thesis was 13 mm, the fresh air content in all concrete mixes

was set to 5%. Although LF was used as a cement replacement, LF was not considered as

a cementitious material in water-to-cement ratio calculation.

For each mix design, concrete, mortar and paste specimens were prepared. The paste

specimens were used for the heat of hydration measurements and thermal analysis. Mortar

specimens were used to evaluate the strength evolution from 12 hours to 28 days. In the

paste and mortar specimens, no admixtures were used, to minimize variation in the results

due to admixture dosages.

Table 4.1: Chemical and Physical Properties of Cements and SF

Chemical and Physical Properties Cement Type

SF GU HE

SiO2 (%) 19.25 19.10 92.1

Al2O3 (%) 5.33 5.18 0.30

Fe2O3 (%) 2.41 2.35 0.60

CaO (%) 62.78 61.60 0.80

MgO (%) 2.36 2.35 0.70

SO3 (%) 4.01 4.26 0.20

Na2Oeq (%) 0.99 1.01 0.92

C3S (%) 58.55 55.15 ---

C3A (%) 10.04 9.75 ---

C4AF (%) 7.34 7.14 ---

C2S (%) 11.03 13.18 ---

LOI at 1150 °C (%) 2.27 2.10 2.00

Blaine (m2/kg) 392 514 ---

Limestone Content (CaCO3) 2.50 3.50 ---



17µm 3µm

LOI at 1050°C (%) 42.8 42.4

CaCO3 (%) 95.0 96.0

MgCO3 (%) 2.0 2.0

% Retained on 44μm mesh 15.000 0.003

Moisture Loss at 110°C (%) 0.03 0.08

Blaine (m2/kg) 475 1125

Specific Gravity 2.7 2.7

88

Table 4.3: Concrete Mix Details

MIX ID

Cementitious Materials LF

w/c Cement SF

(%)

Interground

(%)

Blended

Type % % Size

GU CSA Type

GU

95 5 2.5 0 --- 0.34

GU-17µm 80 5 2.5 15 17 0.34

GU-3µm 80 5 2.5 15 3 0.34

HE CSA Type

HE

95 5 3.5 0 --- 0.34

HE-17µm 80 5 3.5 15 17 0.34

HE-3µm 80 5 3.5 15 3 0.34

Table 4.4: Weight Proportions of Concrete Mixes

Mix ID Cement SF

LF Coarse

Agg. Water Sand/

Aggregate

AEA HRWR Size

(μm) kg/m3

kg/m3 kg/m3 ml/100kg

GU 427.5 22.5 --- --- 950 150.3 0.47 37 900

GU-17µm 360 22.5 17 67.5 950 123.0 0.47 120 2300

GU-3µm 360 22.5 3 67.5 950 123.0 0.47 148 2450

HE 427.5 22.5 --- --- 950 150.3 0.47 45 1000

HE-17µm 360 22.5 17 67.5 950 123.0 0.47 195 2350

HE-3µm 360 22.5 3 67.5 950 123.0 0.47 240 2500

4.2.3. Mixing and Curing

Mortars and pastes were prepared by blending cement, sand and LF (when used) for 2

minutes in a 10-litre mortar mixer followed by the addition of water and mixing for 4

minutes. Concrete mixing was done in a 30-litre drum mixer. Each SCC mix design was

prepared in two 30-litre batches. SCC mixes were prepared by blending coarse aggregate

and sand with 80% of water for 1 minute followed by the addition of cement and the

remaining 20% of water containing AEA and mixing for 3 minutes. Following that, HRWR

was added and the concrete was mixed for an additional 4 minutes.

The curing regime consisted of steam curing for 12 or 16 hours at a maximum holding

temperature of 55°C and 95% relative humidity (RH) followed by moist curing at 100%

RH and 23°C. The steam curing was conducted in a 0.45 m3 environmental chamber

manufactured by Cincinnati Sub-Zero with a built-in steam generator to control the relative

89

humidity. To prevent any thermal damage due to the early application of steam curing,

initial setting time for each mix was measured [18]. The steam curing was applied after the

initial setting time (preset period of 2 hours at 23°C and 95% RH). The steam curing

regimes are presented in Figure 4.1. After the 2-hour preset period, all specimens were

steam cured in the following sequence:

i. heating to 55°C in 2 hours (16°C /hour) while maintaining 95%RH

ii. holding the temperature at 55°C while maintaining 95%RH for 10 hours for the

16-hour curing regime or 6 hours for the 12-hour curing regime.

iii. cooling to 23°C in 2 hours (16°C /hour) while maintaining 95%RH (in the

chamber)

The temperature of the chamber was controlled to maintain the required internal

temperature of the samples, using Type T thermocouples embedded in the samples at the

centroid. This was to ensure that the internal temperature of the specimens was following

the steam curing regime presented in Figure 4.1.


10

15

20

25

30

35

40

45

50

55

60

0 2 4 6 8 10 12 14 16

Tem

per

ature

(°C

)

Time (hour)



90

4.2.4. Test Methods

4.2.4.1. Mortar and Paste Testing

Normal Consistency and Initial Setting Time: The normal consistency and initial setting

time were measured according to ASTM C187-11 and ASTM C191-08, respectively.

Heat of Hydration: The heat of hydration was measured for 72 hours at 23°C using a TAM

Air isothermal calorimeter manufactured by Thermometric in accordance with ASTM

C1702-09 Method B. For each mix design, three paste samples were tested.

Thermal Analysis: The TG/DTA analysis was conducted using SA Simultaneous Thermal

Analyzer heated to 1145°C at a heating rate of 10°C/min. For each mix design, three

TG/DTA tests were conducted. The paste specimens were tested after 16 hours of steam

curing and after 28 days (16 hours of steam curing followed by moist curing in limewater

until 28 days). Before testing, the specimens were freeze-dried. The freeze-drying

consisted of two steps. Firstly, the specimens were placed in liquid nitrogen to stop the

hydration reactions. Secondly, the specimens were placed under vacuum at -10°C. The

freeze-drying of the specimens continued until a constant mass (less than 0.1% change in

a 24-hour period) was achieved. The mass of the tested samples for all mix designs was

kept constant at 100 ± 0.4 mg. The calcium hydroxide (Ca(OH)2), calcium carbonate

(CaCO3) and the non-evaporable water contents were measured. The non-evaporable water

content was used to calculate the degree of hydration. The Ca(OH)2 content and the degree

of hydration were used to evaluate the hydration products to provide a relative comparison

between mix designs. CaCO3 content was used to evaluate the reactivity of LF. The initial

content (prior to mixing) of CaCO3 was calculated according to Equation 4.1. The

percentage by weight (wt%) of Ca(OH)2 and CaCO3 were calculated using stoichiometry

[19]. The mass loss due to the decomposition of CaCO3 between 680 to 800°C was used

to calculate the final CaCO3 content, as presented in Equation 4.2 [23]. The mass loss due

to Ca(OH)2 decomposition between 450 to 500°C was used to calculate the wt% of

Ca(OH)2, as presented in Equation 4.3 [20]. The difference between the initial and the final

CaCO3 content was assumed to be the portion of LF that was consumed in the reaction

with monosulfate and aluminate phases in the hydrated cement to form calcium

monocarboaluminate [21,22]. The degree of hydration was calculated by dividing the mass

91

loss between 23°C and 550°C by the maximum theoretical non-evaporable water (i.e.,

0.23), as presented in Equation 4.4 [23,24].


𝑇𝑜𝑡𝑎𝑙 𝑀𝑎𝑠𝑠 (𝑐𝑒𝑚𝑒𝑛𝑡+𝐿𝐹+𝑤𝑎𝑡𝑒𝑟)× 100 Eq. 4.1


Molar Mass of CO2 Eq.4.2

Ca(OH)2 Content (wt%) = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (450 − 500°C ) ×Molar Mass of Ca(OH)2

Molar Mass of H2O Eq.4.3

Degree of Hydration = 𝑀𝑎𝑠𝑠 𝑙𝑜𝑠𝑠 (23−550°C )

0.23 Eq.4.4

Mortar Compressive Strength: The cube compressive strength of mortar was measured in

accordance with ASTM C109-12. For each mix design, three cubes were tested at 12 hours

and 16 hours and at 3, 7 and 28 days.

4.2.4.2. Concrete Testing

Plastic Properties: The slump flow, T-50 and VSI were measured according to CSA A23.2

[25]. The J-ring and column segregation tests were conducted in accordance with ASTM

C1621-09 (CSA A23.2-20C) and ASTM C1610-10, respectively. The L-box was measured

in accordance with (MTO LS-440) [26]. The fresh air content was measured according to

ASTM C231-10 (CSA A23.2-4C).

Hardened Properties: The hardened properties were measured using 100 mm × 200 mm

cylinders according to CSA A23.2-3C. The compressive strength (CSA A23.2-9C), UPV

(ASTM C597-09), elastic modulus (ASTM C469-04) and density (ASTM C138-10) were

measured at 12 and 16 hours and at 3, 7 and 28 days.

Transport Properties: The transport properties were evaluated using RCPT at 28 days in

accordance with ASTM C 1202-10.

Durability Performance: The linear shrinkage was measured according to MTO LS-435

[26]. In this test, following steam curing, concrete prisms (75 mm × 75 mm × 285 mm)

were cured in limewater at 23°C for 7 days before exposure to 50% RH at 23°C. Sulfate

resistance was evaluated using ASTM C1012-10. The rapid freeze-thaw test was conducted

in accordance with ASTM C666-08. Salt scaling test was conducted in accordance with

MTO LS-412 [26]. In this test, at the end of steam curing, concrete slabs (300 × 300 × 75

92

mm) were moist cured (98% RH at 23°C) for 14 days followed by air curing (45-55% RH

at 23°C) for another 14 days. At the end of the 28 days, the concrete slabs were exposed to

50 freeze-thaw cycles. Each cycle consists of 16 hours at -18°C followed by 8 hours at

23°C and 50% RH.


4.3.1. Normal Consistency and Initial Setting Time

The results of the normal consistency and the initial setting time are presented in Table 4.5.

In general, the increase in cement fineness observed when comparing GU versus HE mixes

increased the normal consistency irrespective of the presence or fineness of LF. The

amount of water required to achieve normal consistency increased with the addition of LF.

Pastes made with 3µm LF showed a slight increase in the normal consistency compared to

pastes made with 17µm LF. The increase in the normal consistency with finer cement (i.e.,

HE cement) or finer LF was caused by the higher surface area, which increases the required

amount of water to achieve normal consistency.

Table 4.5: Normal Consistency and Initial Setting Time

MIX ID Normal

Consistency

Initial Setting

(mins)

Reduction in Initial Setting

Time* (%)

GU 0.280 94 ---

GU-17µm 0.305 91 3.2

GU-3µm 0.310 81 13.8

HE 0.330 91 3.2

HE-17µm 0.350 89 5.3

HE-3µm 0.355 77 18.1

*Compared to Mix GU

The increase in cement fineness decreased the initial setting time. The addition of LF

decreased the initial setting time for both GU and HE cement pastes. The influence of LF

on the initial setting time was greater in HE cement compared to GU cement. The effect of

LF fineness was more pronounced in the results of the initial setting time compared to the

normal consistency results. Pastes made with 3µm LF showed 12% decrease in the initial

setting time compared to pastes made with 17µm LF. The reduction in the initial setting

93

time with finer cement (i.e., HE cement) or finer LF was caused by the higher surface area,

which accelerates the hydration reactions causing a shorter initial setting time [27]. The

reduction in the initial setting time with the use of HE cement or finer LF reduces the risk

of thermal cracking due to steam curing as the concrete obtains the strength sooner

compared to concrete made with GU cement without LF.

4.3.2. Heat of Hydration

The heat of hydration curves of cement pastes are presented in Figure 4.2. Pastes made

with HE cement showed 40% higher hydration peak compared to counterpart pastes made

with GU cement. This was due to the higher fineness in HE cement, which increases the

hydration rate [28]. Pastes made of GU and HE cement with LF showed higher hydration

peaks compared to the corresponding 100% GU and 100% HE. For pastes made with GU

cement, the addition of LF increased the hydration peak from 4.6 mW/g in mix GU to 4.9

mW/g in mix GU-17µm and 5.1 mW/g in mix GU-3µm. This corresponds to 8% and 13%

increases in the hydration peak when GU cement was replaced by 17µm and 3µm LF,

respectively. For pastes made with HE cement, the addition of LF increased the hydration

peak from 6.1 mW/g in mix HE to 6.7 mW/g in mix HE-17µm and 7.4 mW/g in mix HE-

3µm. This corresponds to an increase of 9% and 21% when HE cement was replaced by

17µm and 3µm LF, respectively. Finer LF (i.e., 3µm) yielded greater heat of hydration

compared to coarser LF (i.e., 17µm). LF size of 3µm showed 4% and 10% higher hydration

peak compared to 17µm LF in GU and HE pastes, respectively. The results indicate that

LF had a greater influence on the heat of hydration in pastes made with HE cement

compared to counterpart pastes made with GU cement. This could be due to the higher

fineness of HE cement compared to GU cement, which reduces the space between cement

particles and allows better utilization of the surface area provided by LF for the

precipitation of hydration products.

94

Figure 4.2: Heat of Hydration of Cement Pastes at 23°C

4.3.3. Thermal Analysis

Ca(OH)2 content: The Ca(OH)2 content measurements are presented in Figure 4.3 (please

refer to Section A.7.1 in Appendix A for the raw data and the statistical analysis). Pastes

made with HE cement showed lower Ca(OH)2 content compared to counterpart pastes

made with GU cement. However, the difference in Ca(OH)2 content between pastes made

with HE and GU cement was greater at 16 hours compared to 28 days. The increase in the

cement fineness in HE cement increases the hydration rate, which allows more Ca(OH)2 to

be available for the pozzolanic reaction with SF. The addition of LF reduced the Ca(OH)2

content for pastes made of GU and HE cement at 16 hours and 28 days. The reduction in

the Ca(OH)2 content with the addition of LF was greater at 16 hours compared to the 28-

day results. The increases in the hydration rate due to the addition of LF increases the

hydration product, which allows more Ca(OH)2 to be consumed sooner in the pozzolanic

reaction with SF. Pastes made with 3µm LF showed 5% lower Ca(OH)2 content compared

to counterpart pastes made with 17µm LF regardless of cement fineness or age. Due to the

high fineness and amorphous structure of SF, the pozzolanic reaction is expected to take

place at the early age of hydration. However, it is mainly controlled by the availability of

0

1

2

3

4

5

6

7

8

0 5 10 15 20

Po

wer

(m

W/g

)

Time (Hour)

GU GU-17µm GU-3µmHE HE-17µm HE-3µm

95

Ca(OH)2 [29]. This explains the greater influence of LF content and cement fineness on the

Ca(OH)2 content at 16 hours compared to the 28-day measurement.

Figure 4.3: Effect of LF Content and Size on Ca(OH)2 Content of Pastes Made with GU

and HE Cements at 16 hours and 28 days

CaCO3 content: The percentage by weight of reacted LF at 16 hours and 28 days is

presented in Figure 4.4 (please refer to Section A.7.1 in Appendix A for the raw data and

the statistical analysis). Pastes made with GU and HE cement showed similar LF reactivity

at 16 hours. At 28 days, the reactivity of LF was slightly higher in pastes made with HE

cement compared to counterpart pastes made with GU cement. At all ages, the highest

reactivity was observed in mix designs made of GU and HE cement with 3µm LF. For all

mix designs, the percentage by weight of reacted LF at 16 hours was approximately half

of the percentage of reacted LF at 28 days. The 16-hour testing was conducted immediately

after steam curing, during which the samples were exposed to a higher temperature at 55°C.

At that temperature, the solubility of LF is reduced compared to 23°C [16]. The reduction

in LF solubility reduces the amount of reacted LF at 16 hours.

6.8

7.0

7.2

7.4

7.6

7.8

8.0

8.2

8.4

8.6

0% Blended LF 15% of 17µm LF 15% of 3µm LF

Ca(

OH

) 2 (

%)

GU-16 Hours HE- 16 Hours GU- 28 Days HE-28 Days

96

Figure 4.4: Effect of LF Content and Size on CaCO3 Content of Pastes Made with GU

and HE Cements a) 16 hours, b) 28 days

Degree of hydration: The degree of hydration results are presented in Figure 4.5 (please

refer to Section A.7.1 in Appendix A for the raw data and the statistical analysis). Pastes

made of HE cement showed a 25% higher degree of hydration compared to counterpart

pastes made of GU cement at 16 hours and 28 days. The higher degree of hydration

observed in HE cement was due to the acceleration in hydration rate at 16 hours. At 28

days, the higher degree of hydration observed with HE cement could be due to the increase

in the surface area in HE cement compared to GU cement. The higher surface area reduces

the thickness of hydration products coating anhydrous cement particles causing a higher

degree of hydration [30]. Although there was a clear effect of LF on the heat of hydration,

Ca(OH)2 content and calcium monocarboaluminate contents, LF content and fineness did

not influence the degree of hydration at 16 hours or 28 days. This could be due to two

factors. Firstly, the increase in hydration rate due to the additional surface area of LF was

-0.5

0.0

0.5

1.0

1.5

2.0


Rea

cted

LF

(w

t%)

GU HEa)

0.0

0.5

1.0

1.5

2.0


Rea

cted

LF

(w

t%)

GU HEb)

97

mainly observed in the first 8 to 10 hours, after which the hydration rate of LF pastes was

lower than paste made without LF as shown in Figure 4.2. Secondly, the reduction in the

cement hydration products “the dilution effect” with LF was compensated for by calcium

monocarboaluminate.

Figure 4.5: Effect of LF Content and Size on the Degree of Hydration of Cement Pastes

4.3.4. Mortar Compressive Strength

The results of the mortar compressive strength are presented in Figure 4.6. Each

compressive strength result is an average of three mortar cubes and the corresponding

coefficient of variation was less than 6% for all mixes (please refer to Section A.7.1 in

Appendix A for the raw data and the statistical analysis). Mortar made with 100% HE

showed greater compressive strength compared to 100%GU at early age (i.e., 12 and 16

hours) as would be expected. At 28 days, the strength of HE and GU mortars was similar.

Mortars made with LF showed higher compressive strength compared to counterpart

mortars made without LF at all ages. This can be explained by the increase in the hydration

rate observed in the heat of hydration results, which increases the early age strength again.

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80


DO

H

GU-16 Hours HE-16 Hours GU-28 Days HE-28 Days

98

However, the gain in the compressive strength with the addition of LF diminished with

time due to the dilution effect [31]. For example, the range of compressive strength for all

mix designs was 54 to 63 MPa at 12 hours and 80 to 84 MPa at 28 days. Further analysis

of the results reveals that the increase in the compressive strength with the addition of LF

was greater in mortars made with GU cement compared to counterpart mortars made with

HE cement. This could be due to the fact that GU cement was coarser than HE cement.

Therefore, the improvement in particle packing was expected to be higher in GU cement

compared to HE cement when LF was added [32]. Mortars made with 3µm LF showed

higher compressive strength from 12 hours to 7 days compared to 17µm LF regardless of

cement fineness. At 28 days, the compressive strength of mortars made with 3µm and

17µm LF was similar.

Based on the results of the heat of hydration, thermal analysis and mortar compressive

strength, the addition of LF improves the hydration kinetics at early age (i.e., 12 and 16

hours) and compressive strength from 12 hours to 28 days. This was due to the increase in

surface area, improved particle packing and the production of calcium

monocarboaluminate.

Figure 4.6: Cube Compressive Strength of Mortars

50

55

60

65

70

75

80

85

0.1 1 10 100

Cub

e C

om

pre

ssiv

e S

tren

gth

(M

Pa)

Age (Days) - Log Scale

GU GU-17µm GU-3µm

HE HE-17µm HE-3µm

12 hrs. 16 hrs.

3 7 28

99

4.3.5. Plastic Properties of Concrete

The plastic properties of concrete are presented in Table 4.6. All concrete mix designs had

a fresh air content of 5 to 5.6% and slump flow of 650 to 680 mm. In addition, all concrete

mix designs showed high stability with VSI ranging from 0 to 0.5 and column segregation

measurements below 3%. The yield of all concrete mixes was approximately 1.0 m3 ±

0.012 m3. The plastic properties of concrete mixes fell within the required ranges based on

CSA and MTO standards, as presented in Table 4.7 with the exception of the L-box test.

Although the L-box ratio was lower than the required limits by CSA or MTO, it was within

the acceptable limit of 0.5 suggested for precast applications by Khayat and Mitchell

(2009) [5]. The increase in cement fineness in HE cement compared to GU cement did not

significantly increase the dosage of HRWR to maintain similar workability. However, the

increase in cement fineness showed a significant increase in the dosage of AEA to maintain

a similar percentage of fresh air content. The addition of LF increased the required dosage

of HRWR and AEA to maintain similar plastic properties to concrete made without LF.

Concrete mixes made with 3µm LF required a higher dosage of HRWR and AEA to

maintain similar workability and fresh air content compared to concrete mixes made with

17µm. The increase in the required HRWR and AEA with HE cement and/or 3µm LF was

due to the increase in surface area, which increases the adsorption of the admixtures and

increases the viscosity of the mix [33].

Table 4.6: Plastic Properties of Concrete Mixes

Mix ID

Plastic Air

Content

(%)

Plastic

Density

(kg/m3)

Slump L-box

(H2/H1)

Column

Segregation

(%) Flow

(mm)

T50

(sec) VSI

J-Ring

(mm)

GU 5.0 2395 680 4 0.5 660 0.67 2.5

GU-17µm 5.5 2431 650 4 0 635 0.58 1.5

GU-3µm 5.2 2439 660 5 0 640 0.50 1.0

HE 5.0 2444 650 5 0.5 638 0.64 1.6

HE-17µm 5.3 2439 680 4 0 660 0.56 1.5

HE-3µm 5.6 2443 650 5 0 630 0.53 0.8

100

Table 4.7: Acceptance Criteria for Plastic Properties of SCC

Test Measure (Unit) Standard Acceptance Limits

Slump Flow Flow Distance (mm) CSA A23.1 (2014) 500-800

J-ring

Difference between

Slump Flow with and

without the J-ring (mm)

MTO SP-SCC (2009) Max. 50mm

CSA A23.1 (2014) Max. 25mm

VSI Visual Assessment MTO SP-SCC (2009) Max. 1.5

L-box Blocking Ratio

MTO SP-SCC (2009) Min. 0.7

CSA A23.1 (2009) Min. 0.8

Khayat and Mitchell

(2009) Min. 0.5

Column Method Static Segregation (%) MTO SP-SCC (2009)

CSA A23.1 (2014) Max. 10%

4.3.6. Hardened Properties of Concrete

Density: Concrete densities are presented in Table 4.8. Each value in the table is the average

of three tests whereas the coefficient of variation was less than 2% (please refer to Section

A.7.3 in Appendix A for the raw data and the statistical analysis). To accurately evaluate

the influence of cement fineness and LF content and fineness, the density was corrected

for 5.0% fresh air content based on Equation 4.5. For example, mix HE-3µm had a fresh

air content of 5.6%. The corrected density, 2470 kg/m3, was greater than the measured

density (2455 kg/m3) based on Equation 4.5.

Corrected density (kg/m3) = Measured Density × [1 +(𝐹𝑟𝑒𝑠ℎ 𝑎𝑖𝑟 𝑐𝑜𝑛𝑡𝑒𝑛𝑡 (%)−5)

100] Eq. 4.5

Corrected density for concrete mix HE-3µm (kg/m3) = 2455 × [1 +(5.6−5)

100] = 2470 kg/m3

Table 4.8: Density of Concrete Mixes

Mix ID

Density (kg/m3) Average

Density

(kg/m3)

Corrected

Average Density

(kg/m3) 12 hrs. 16 hrs. 3 days 7 days 28 days

GU 2356 2346 2351 2360 2375 2358 2358

GU-17µm 2360 2346 2357 2353 2383 2360 2372

GU-3µm 2444 2462 2439 2455 2458 2452 2457

HE 2405 2414 2432 2415 2431 2419 2419

HE-17µm 2421 2415 2430 2442 2440 2430 2437

HE-3µm 2458 2460 2449 2448 2460 2455 2470

101

The following discussion is based on corrected densities. Concrete mix designs made with

HE cement showed higher density compared to counterpart mixes made with GU cement.

The addition of LF increased the density of concrete mixes made with GU and HE cements.

The increase in the density was 1% and 4% for concrete mixes made of GU cement with

17µm and 3µm LF, respectively, compared to 100% GU. Concrete made of HE cement

with 17µm and 3µm LF showed an increase of 1% and 2% in the density, respectively,

compared to the 100% HE. The influence of LF on the density of GU mixes was higher

compared to counterpart mixes made with HE cement. This indicates that the improvement

in particle packing was greater in the coarser cement (i.e., GU cement) when LF was added.

Concrete mixes made of GU and HE cement with 3µm LF showed a 4% and 1% increase

in density, respectively, compared to counterpart mixes made with 17µm. The density

results indicate that the greater difference between LF and cement finenesses, the greater

increase in concrete density.

Compressive strength: The results of the compressive strength are presented in Figure 4.7.

Each compressive strength result is an average of three cylinders and the corresponding

coefficient of variation was less than 4% for all mixes (please refer to Section A.7.3 in

Appendix A for the raw data and the statistical analysis). As might be expected, concrete

mixes made with HE cement showed higher compressive strength at 12 hours to 7 days

compared to GU mixes. At 28 days, the compressive strength of HE and GU mixes was

similar. Concrete mixes made of GU and HE cement with LF showed higher early age (i.e.,

12 and 16 hours) compressive strength compared to counterpart mixes made without LF.

The higher early age compressive strength with HE cement and/or LF can be attributed to

the increase in hydration rate, which was observed in the heat of hydration results and in

agreement with the results obtained from the mortar compressive strength testing. Concrete

made with GU cement and 17µm LF showed similar strength to 100% GU at 3 days. At 7

and 28 days, the compressive strength was lower than 100% GU. Concrete made with GU

cement and 3µm LF showed similar strength to 100% GU at 7 and 28 days. Concrete mixes

made of HE cement and LF showed similar compressive strength to 100% HE at 3, 7 and

28 days regardless of LF fineness. Concrete mixes made of GU and HE cement with 3µm

LF showed higher compressive strength at 12 hours to 7 days compared to counterpart

mixes made with 17µm. At 28 days the compressive strength of GU and HE mixes made

with 3µm and 17µm LF was similar. The effect of LF on the compressive strength was

102

mainly influenced by increasing the hydration rate and the production of calcium

monocarboaluminate, which increase the early age strength (i.e., 12 and 16 hours) and the

dilution effect, which was observed at later age (i.e., 3 to 28 days). Based on the results,

the dilution effect caused by LF could be controlled by increasing the fineness of the

cement or LF.

Figure 4.7: Compressive Strength of Concrete Cylinders

UPV: The UPV was used to assess the density and homogeneity of concrete. The quality

of concrete can be classified as excellent, good and doubtful for the UPV values of 4500

m/s and above, 3500 m/s to 4500 m/s and 3000 m/s to 3500 m/s, respectively [34,35]. The

results of the UPV are presented in Figure 4.8. Each UPV value is an average of three tests

and the corresponding coefficient of variation was less than 3% for all mixes (please refer

to Section A.7.3 in Appendix A for the raw data and the statistical analysis). All concrete

mixes exhibited UPV values between 4500 m/s and 4900 m/s at 16 hours and

approximately 5100 m/s at 28 days. Therefore, all mixes can be classified as excellent

35

40

45

50

55

60

65

70

75

0.1 1 10 100

Co

mp

ress

ive

Str

ength

(M

Pa)


GU GU-17µm GU-3µm

HE HE-17µm HE-3µm

2873

16 hrs.12 hrs.

103

concrete. Concrete mixes made of HE cement showed higher UPV at 12 hours to 7 days

compared to counterpart mixes made with GU cement. At 28 days, all concrete mixes made

of HE and GU cement had similar UPV, as presented in Figure 4.8. The addition of LF

increased the UPV at 16 hours to 7 days for concrete mix designs made with GU and HE

cement. At 28 days, no effect of LF was observed on the UPV of concrete mixes made of

GU and HE cement. The increase in the UPV with the addition of LF was greater in

concrete mixes made of GU cement compared to concrete mixes made of HE cement.

Concrete mixes made of 3µm LF had higher UPV values compared to counterpart mixes

made of 17µm LF. The UPV results are in agreement with the concrete compressive

strength and density results.

Figure 4.8: UPV Results of Concrete Mixes

Elastic Modulus: The results of the elastic modulus are presented in Table 4.9. Each value

in the table is an average of three tests and the corresponding coefficient of variation was

less than 4% for all mixes (please refer to Section A.7.3 in Appendix A for the raw data

and the statistical analysis). Concrete mix designs made with HE cement showed higher

elastic modulus than counterpart mixes made with GU cement at 12 hours to 7 days, as

shown in Table 4.9. The higher elastic modulus in HE mixes was due to the higher early

4000

4200

4400

4600

4800

5000

5200

5400

0.1 1 10 100

UP

V (

m/s

)


GU GU-17µm GU-3µm

HE HE-17µm HE-3µm

28 73

16 hrs.12 hrs.

104

age strength compared to GU mixes. At 28 days, all concrete mixes had an elastic modulus

of approximately 41 GPa. Concrete mix designs made with LF showed improved elastic

modulus compared to concrete mixes without LF at 12 hours. At 16 hours to 28 days, the

elastic modulus of concrete mix designs made with and without LF was similar. The elastic

modulus results are in agreement with the concrete compressive strength and UPV results.

As expected, a strong correlation was observed between elastic modulus, UPV and

compressive strength, as presented in Figure 4.9. In this figure, a linear relationship was

observed between the elastic modulus, UPV and the compressive strength with R2 of 0.85.

In Figure 4.9, the scale of the UPV and compressive strength axes were adjusted to align

the two regression lines representing the UPV-elastic modulus relationship and the

compressive strength- elastic modulus relationship.

Table 4.9: Elastic Modulus of Concrete Mixes

Mix ID Elastic Modulus (GPa)

12 hrs. 16 hrs. 3 days 7 days 28 days

GU 26.1 32.6 35.0 37.3 40.7

GU-17µm 27.4 32.8 35.6 37.1 41.0

GU-3µm 31.3 34.8 36.0 38.1 41.0

HE 31.6 35.1 37.1 39.0 41.4

HE-17µm 33.4 35.4 37.2 38.9 40.6

HE-3µm 34.4 36.1 38.4 39.7 41.7

105

Figure 4.9: Relationship between Elastic Modulus, UPV and Compressive Strength

4.3.7. Transport Properties of Concrete

The RCPT values of concrete are presented in Figure 4.10 (please refer to Section A.7.4 in

Appendix A for the raw data and the statistical analysis). Concrete mix designs made of

HE cement with and without LF showed lower (13 to 23%) RCPT values compared to

counterpart mixes made with GU cement. Concrete mix designs made with LF showed

lower RCPT values compared to the corresponding control mix (i.e., 100% GU or 100%

HE). Concrete mix designs made of GU cement with 17µm and 3µm LF showed 28% and

33% decrease in the RCPT values, respectively, compared to 100% GU. HE concrete mixes

made with 17µm and 3µm LF showed a reduction of 18% and 30% in the RCPT values,

respectively, compared to 100% HE. This indicates that LF had a greater influence on the

RCPT values of GU mixes compared to HE mixes. This observation was also noted in the

compressive strength, UPV and density results. Concrete mixes made with 3µm LF showed

lower RCPT values compared to counterpart mixes made with 17µm. The decrease in the

RCPT values with an increase in cement or LF finenesses could be due to two factors.

Firstly, concrete made with finer cement or LF showed improved density, which indicates

lower pore volume and better particle packing compared to counterpart mixes made with

coarser cement or LF. Secondly, the percentage of calcium monocarboaluminate was

R² = 0.85

25

35

45

55

65

75

85

4100

4250

4400

4550

4700

4850

5000

5150

5300

5450

25 30 35 40 45

Co

mp

ress

ive

Str

ength

(M

Pa)

UP

V (

m/s

)

Elastic Modulus (GPa)

UPV Compressive Strength

106

higher in mixes made with finer cement or LF compared to counterpart mixes made with

coarser cement or LF at 28 days.

Figure 4.10: RCPT Values of Concrete Mixes at 28 Days

4.3.8. Durability Performance of Concrete

Linear shrinkage: The results of the linear shrinkage testing are presented in Figure 4.11.

Each curve in the figure is the average of three prisms (please refer to Section A.7.5 in

Appendix A for statistical analysis). Concrete mix designs made with HE cement showed

lower linear shrinkage compared to counterpart mixes made with GU cement. The addition

of LF reduced the linear shrinkage in concrete mix designs made with GU or HE cement.

The reduction in linear shrinkage in the presence of LF was greater in concrete mix designs

made with GU cement compared to HE cement mixes. Linear shrinkage decreased when

the LF size was reduced from 17μm to 3μm.

The increase in cement fineness and the addition of LF decreased the permeability. This

makes the loss of free water (gained during water immersion before the exposure to 50%

RH) in concrete more difficult and thus reduces the linear shrinkage. In addition, concrete

made with LF had less total water content than corresponding control mixes without LF.

0

100

200

300

400

500

600

700


28

Day

RC

PT

(C

oulo

mb

s)

GU HE Series3

107

This may lead to a higher initial free water content in concrete mixes made without LF.

Nevertheless, since the concrete had a low water-to-cement ratio and was steam cured for

16 hours, it is expected that most of the free water in the mix was consumed in the hydration

reaction. However, no laboratory testing has been conducted to confirm this assumption.

The results of the linear shrinkage are in agreement with the findings in the literature

[36,37].

Figure 4.11: Linear Shrinkage of Concrete Mixes

Figure 4.12 presents the relationship between LF reactivity, RCPT and linear shrinkage

results at 28 days. The figure reveals that the increase in LF reactivity reduces the

permeability and linear shrinkage. This was due to the production of calcium

monocarboaluminate that fills the voids and thus reduces the permeability of concrete.

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0 10 20 30 40 50 60 70 80

Lin

ear

Shri

nkag

e (%

)

Age (Days)

GU GU-17µm GU-3µmHE HE-17µm HE-3µm

108

Figure 4.12: Effect of LF Reactivity on RCPT and Linear Shrinkage of Concrete Mixes at

28 Days

Sulfate resistance: The results of the sulfate expansion are presented in Figure 4.13. Each

curve in the figure is the average of three mortar bars (please refer to Section A.7.5 in

Appendix A for the raw data and statistical analysis). Mortar mix designs made with HE

cement showed lower expansion compared to counterpart mixes made with GU cement.

No influence of LF was observed on the sulfate expansion at the end of the 6-month

exposure period. The expansion of GU and HE mix designs was approximately 0.038%

and 0.031%, respectively, which was less than the moderate sulfate expansion limit (0.1%

after 6 months of exposure) set by ASTM C1012. By comparing the expansion curves in

Figure 4.13, it was observed that the deviation between GU and HE mix designs occurred

in the first week of exposure and thereafter the slope (i.e., the rate of expansion) of GU and

HE mixes was similar. This could be explained by the higher rate of hydration in mix

designs made with HE cement compared to GU, especially at the early age. It is important

to note that all specimens were placed in the sulfate solution at the same cube compressive

strength (20 ± 1 MPa) as required by ASTM C1012. This was achieved by reducing the

accelerated curing time at 35 ºC from 14 hours in GU cement to 13 hours in HE cement.

Although the SO3 content was high in GU and HE cements (4.01% and 4.26%,

respectively), the cement showed lower sulfate expansion than the limit set for moderate

0.010

0.012

0.014

0.016

0.018

0.020

0.022

0.024

0.026

0.028

0.030

100

200

300

400

500

600

700

0.0 0.5 1.0 1.5 2.0

Lin

ear

Shri

nkag

e at

28

Day

s (%

)

RC

PT

at

28

Day

s (

Co

ulo

mb

s)

Reacted LF at 28 Days (wt%)

RCPT Linear Shrinkage

109

sulfate resistance cement. This can be attributed to the presence of SF, which has two main

effects. Firstly, SF decreases the permeability through the production of secondary calcium

silicate hydrate (CSH). Secondly, SF reduces the Ca(OH)2 content, which is consumed in

the pozzolanic reaction. This finding is in agreement with the literature [38,39].

Figure 4.13: Sulfate Expansion (ASTM C1012) of Mortars Made of GU and HE Cements

with/without LF

Freeze-thaw and salt scaling resistance: The freeze-thaw and salt scaling resistance of

concrete are presented in Table 4.10. Each value in the table is the average of two prisms

for the freeze-thaw test or the average of two slabs for the salt scaling test (please refer to

Section A.7.5 in Appendix A for the raw data and statistical analysis). All concrete mix

designs showed high resistance to freeze-thaw cycles (durability factor >98% after 300

cycles). According to Ontario Provincial Standard Specification (OPSS) 1821, the

maximum allowable mass loss due to the salt scaling value is 0.80 kg/m2 [40]. All concrete

mix designs showed a lower salt scaling value compared to OPSS 1821 limit. All mix

designs showed a salt scaling value of approximately 0.2 kg/m2 except for concrete mixes

made with GU cement and LF where the salt scaling was approximately 0.4 kg/m2. The

addition of LF or increase in cement fineness did not impact the freeze-thaw or deicer salt

scaling properties.

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Len

gth

Chan

ge

(%)

Age (weeks)

GU GU-17µm GU-3µm HE HE-17µm HE-3µm

Moderate Sulfate Resistance Expansion Limit (0.1% at 6 Months)

110

Table 4.10: Freeze-Thaw and Salt Scaling Resistance of SCC Mix Designs

Mix ID

Freeze-Thaw Resistance Salt Scaling

Mass Loss

(kg/m2) Length Change (%)

Durability Factor

(%)

GU 0.0110 98.0 0.019

GU-17µm 0.0132 98.1 0.444

GU-3µm 0.0120 97.9 0.376

HE 0.0120 99.0 0.253

HE-17µm 0.0167 97.0 0.198

HE-3µm 0.0167 97.1 0.204

4.4. Statistical Analysis

A multiple linear regression analysis was conducted to identify which independent variable

(cement fineness, LF content and LF size) had a greater influence on the dependent

variables (hardened and transport properties). The analysis was conducted at a confidence

level of 95%, as presented in Table 4.11. For each set of data representing an independent

variable, the data were normalized (i.e., dividing by the highest value). The value of the

beta coefficient for each independent variable was used to identify the influence on the

dependent variable [41]. The highest beta coefficient precedes the most influential

independent variable. Table 4.12 presents the controlling variables influencing mechanical

properties (i.e., compressive strength, UPV and elastic modulus) and transport properties

(i.e., RCPT). From this table, it was observed that cement fineness was the most influential

variable on mechanical and transport properties. It was also observed that LF content and

fineness were the second and third most influential variables on the mechanical and

transport properties of concrete.

111

Table 4.11: Multiple Linear Regression Analysis

Property Prediction Equation R2

Mechanical Properties

Compressive Strength

Early Age

(12 and 16 hours) Concrete Compressive Strength (MPa) =

50.0 × C + 5.3 × LFC − 5.5 × LFS + 31.1 × As − 23.2 0.93

Later Age

(3, 7 and 28 days) Concrete Compressive Strength(MPa) =

14.1 × C + 1.2 × LFC − 3.0 × LFS + 0.4 × Am + 49.1 0.85

UPV

Early Age

(12 and 16 hours) Concrete UPV (m/s) =

1723 × C + 299 × LFC − 125 × LFS + 724 × As + 2375 0.92

Later Age

(3, 7 and 28 days) Concrete UPV (m/s) =

793 × C + 113 × LFC − 112 × LFS + 9 × Am + 4131 0.82

Elastic Modulus

Early Age

(12 and 16 hours) Concrete Elastic Modulus (GPa) =

18.50 × C + 3.20 × LFC − 2.30 × LFS + 15.13 × As +1.40

0.89

Later Age

(3, 7 and 28 days) Concrete Elastic Modulus (GPa) =

7.12 × C + 0.89 × LFC − 0.90 × LFS + 0.16 × Am

+ 29.89

0.90

Transport Property

Early Age

(12 and 16 hours) RCPT (Coulombs) = −490 ∙ C − 177 ∙ LFC + 51 ∙ LFS −165 ∙ As − 70 ∙ Am + 1221

0.97

Where:

C: cement fineness coefficient = 𝐵𝑙𝑎𝑖𝑛𝑒 𝐹𝑖𝑛𝑒𝑛𝑒𝑠𝑠 (

𝑚2

𝑘𝑔)

514 (i.e., for GU = 0.81 and HE

=1.00)

LFC: blended LF content coefficient = 𝐿𝐹 𝑐𝑜𝑛𝑡𝑒𝑛𝑡 (%)

15

LFS: blended LF size coefficient = 𝐿𝐹 𝑠𝑖𝑧𝑒 (µ𝑚)

17

As: steam curing period coefficient = steam curing period (ℎ𝑜𝑢𝑟𝑠)

16

Am: moist curing period coefficient = moist curing period (𝑑𝑎𝑦𝑠)

28

112

Table 4.12: Controlling Variables of Concrete Mixes

Property

Controlling Variables

(1= highest influence , 4= lowest influence)

1 2 3 4

Mechanical Properties

Compressive Strength

Early Age (12 and 16 hours) C AS LFS LFC

Later Age (3, 7 and 28 days) C LFS LFC Am

UPV

Early Age (12 and 16 hours) C AS LFC LFS

Later Age (3, 7 and 28 days) C LFC LFS Am

Elastic Modulus

Early Age (12 and 16 hours) C AS LFC LFS

Later Age (3, 7 and 28 days) C LFS LFC Am

Transport Property

RCPT at 28 Days C LFC/ AS Am LFS

C: Cement type

LFS: LF size

LFC: LF content

Am: Moist curing duration

As: Steam curing duration

4.5. Conclusions

(i) The early age (i.e., 12 and 16 hours) hardened properties (i.e., compressive strength,

ultrasonic pulse velocity, density and elastic modulus) of concrete mix designs were

improved with the addition of limestone filler and increasing cement fineness. No

influence of limestone filler or cement fineness on the hardened properties was

observed at later ages (i.e., 3 to 28 days).

(ii) Limestone filler reduced the chloride permeability and linear shrinkage of concrete.

This reduction was attributed to the increase in concrete density and the production

of calcium monocarboaluminate.

(iii) Concrete made with finer limestone filler (i.e., 3µm) had improved hardened,

transport properties and durability performance compared to concrete made with

coarser limestone filler (i.e., 17µm).

(iv) Concrete mix designs made with limestone filler showed similar durability

performance with respect to sulfate attack, freeze-thaw cycles and salt scaling

compared to control mix designs without limestone filler.

113

(v) Based on statistical analysis, the most influential variable on mechanical and

transport properties was cement fineness followed by limestone filler content and

fineness.

(vi) Based on the findings of this chapter, the use of 15% limestone filler (17µm and

3µm) can enhance the early age hardened properties of SCC compared to the same

mixture without limestone filler. Furthermore, the use of 15% limestone filler

(17µm and 3µm) did not adversely impact the durability performance.





acknowledge Holcim Canada for providing the cement and Omya Canada for providing

the limestone, Euclid Admixture Canada Inc. for providing the chemical admixtures and

Dufferin Aggregates for providing the sand and coarse aggregate.

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[38] Zeli, J., Krstulovic, R., Tkalcec, E., and Krolo, P. (1999). Durability of the Hydrated

Limestone - Silica Fume Portland Cement Mortars under Sulphate Attack. Cement

and Concrete Research, Vol. 29, No. 6, pp. 819–826.

[39] Sezer, G. (2012). Compressive Strength and Sulfate Resistance of Limestone and/or

Silica Fume Mortars. Construction and Building Materials, Vol. 26, No. 1, pp. 613–

618.

[40] MTO-SP-SCC (2013). OPSS 1821 Material Specification for Precast Reinforced

Concrete Box Culverts and Box Sewers. Ministry of Transportation, Ontario,

Canada.

[41] Sirkin, R. (2006). Statistics for the Social Sciences, Sage Publications, 3rd Edition,

pp. 438–478.

117

Chapter 5 - Delayed Ettringite Formation in Self-Consolidating Concrete Containing Limestone Filler

Abstract

This chapter investigates the influence of limestone filler on the early and later age

hardened properties, transport properties and durability performance of self-consolidating

concrete steam cured at different temperatures. Four types of cement, namely CSA type

GU, HE, GUL and HS were used. Limestone filler with two nominal particle sizes of 17µm

and 3µm were used to replace 15% of cement by weight. All concrete mixes had 5% silica

fume and water-to-cement ratio of 0.34. Concrete specimens were steam cured at a

maximum temperature of 55°C, 70°C and 82°C. All steam curing regimes had a total

duration of 16 hours. The hardened properties of concrete were evaluated using

compressive strength and ultrasonic pulse velocity tests at 16 hours and at 28 and 300 days.

The transport properties were evaluated using rapid chloride permeability test at 28 and

300 days. The durability performance of concrete was assessed by measuring concrete

expansion and concrete resistance to freeze-thaw cycles. The concrete expansion in water

at 23°C was measured for 300 days followed by freeze-thaw testing for 300 cycles. The

results showed that limestone filler increases the 16-hour compressive strength and

ultrasonic pulse velocity when concrete was steam cured at 55°C. Limestone filler did not

have any significant adverse effect on the later age (28 days to 300 days) compressive

strength or ultrasonic pulse velocity regardless of steam curing temperature. The

permeability of concrete at 28 and 300 days was reduced in the presence of limestone filler.

Concrete mixes steam cured at 82°C expanded and developed microcracks after 300 days.

This expansion and cracking caused a significant reduction in the freeze-thaw resistance

compared to concrete mixes steam cured at 55°C.

Keywords: self-consolidating concrete, limestone filler, steam curing, compressive

strength, delayed ettringite formation, freeze-thaw.

118

5.1. Introduction

The precast/prestressed industry in Canada, which started in the 1950’s, has grown

significantly to become a 2 billion dollars’ industry in 2014 [1,2]. The shorter construction

period and the better concrete quality are two of the main advantages of the

precast/prestressed applications compared to cast-in-place applications [3]. In the

precast/prestressed plants, concrete curing is usually carried out in a tent with a limited

space that can accommodate a certain number of elements. The turnaround time including

casting, curing and demolding is typically 24 hours [4,5].

The use of self-consolidating concrete (SCC) in precast/prestressed applications can reduce

the turnaround time [6]. This time saving is a result of reduced required labour, surface

finishing, and noise and congestion at casting location [7]. However, due to the higher

cement content, SCC has a greater cost and negative environmental impact compared to

traditional concrete [8]. The use of a filler material such as limestone filler (LF) as a cement

replacement can reduce the cost and the negative environmental impact of concrete [9,10].

In the precast/prestressed applications, to maintain the production schedule, steam curing

is often applied to achieve the required demolding compressive strength. During steam

curing, the internal temperature of the concrete elements can rise to a temperature that

ranges between 55°C and 85°C [11,12]. The greater the steam curing temperature the

higher the early age strength and thus shorter curing time. However, concrete exposed to

an elevated temperature at early age can be vulnerable to degradation due to delayed

ettringite formation (DEF) [13,14].

DEF cannot occur without three main conditions. These conditions are (i) the exposure to

elevated temperature at early age, (ii) the existence of enough sulfate in the system and (iii)

a supply of moisture [15,16,17]. The increase in the temperature increases the amount of

sulfate ions adsorbed by CSH [15]. The ability of CSH to adsorb the sulfate ions increases

with the increase in pH (mainly linked to the alkali content in the cement) [18,19]. When

the temperature drops down, the sulfate ions are slowly released. In the presence of sulfate

ions and moisture, monosulfate transform to ettringite. Ettringite forming in the paste

causes the paste to expand and crack. This ettringite is defined as DEF [20]. A secondary

ettringite can also form in cracks and air voids. However, this does not cause any damage

since the secondary ettringite recrystallizes in pre-existing cracks [20]. The literature

119

indicates several other factors that could impact the damage due to DEF. The use of some

pozzolanic materials or SCM can reduce the vulnerability to DEF [21,22]. Entrained air

voids have been reported to accommodate some of the secondary ettringite formation,

however, it does not prevent DEF [23,24].

Although the main factors influencing DEF have been well identified in the literature, three

areas related to DEF still require more research. Firstly, the critical maximum temperature

after which DEF is a concern vary over a wide range. Studies have reported 60°C to 65°C

as a safe limit to prevent DEF [15,25,26] while other studies suggested that the temperature

limit should be within the range of 65°C to 75°C [14,27,28]. This wide range of

temperatures reported in the literature is reflected on the temperature limitations set in the

local and international standards. For example, the Canadian Standard Association CSA

A23.4 sets the maximum steam curing temperature in wet conditions to 60°C, while

Precast/prestressed Concrete Institute (PCI) and Portland Cement Association (PCA) set

the limit to 65°C and 71°C, respectively [12]. Furthermore, many of the departments of

transportation in the USA have a limit on the maximum curing temperature that ranges

from 71°C to 85°C [12]. Secondly, the influence of LF on concrete expansion due to DEF

is not clear. LF has been reported to increase the resistance to DEF [29] while other studies

report reduced resistance to DEF [30,31]. Thirdly, there is limited information in the

literature on how the expansion and damage due to DEF impact the freeze-thaw resistance

of concrete. The aim of this chapter is to contribute toward a better understanding of the

above mentioned three areas. This will be achieved by studying the influence of steam

curing temperature and the presence of LF on concrete expansion due to DEF. In addition,

the influence of the expansion due to DEF on the freeze-thaw resistance of concrete is

assessed.


5.2.1. Materials

Four types of cement were used, namely CSA type GU, HE, GUL and HS cement. GU,

HE and GUL cements were supplied by Holcim Canada while HS cement was supplied by

Lafarge Canada. The physical and the chemical composition of the cement are presented

in Table 5.1. GU and HS cements have approximately similar Blaine fineness (GU = 392

m2/kg and HS = 401 m2/kg), however, the total sulfate and alkali contents were different

120

(sulfate content: GU = 4.0%, HS = 2.0% and alkali content: GU = 1.02%, HS = 0.60%).

The reason for including HS cement in this thesis is to evaluate the influence of LF on

concrete expansion when cements of different composition are used. The silica fume (SF)

used was an undensified powder supplied by SKW Canada. The physical and the chemical

properties of cement and SF are presented in Table 5.1. Two LF with nominal particle sizes

of 17µm and 3µm were used (corresponding to a Blaine fineness of 475 m2/kg and 1125

m2/kg, respectively). LF was supplied by Omya Canada. The chemical and physical

properties of LF are presented in Table 5.2. The fine aggregate was natural sand with a

specific gravity of 2.72 and a fineness modulus of 2.84. The coarse aggregate was crushed

limestone with a maximum size of 13 mm. The fine and coarse aggregates were supplied

by Dufferin Aggregates. Two admixtures supplied by Euclid Chemical Company Canada

were used, namely high-range water reducer (HRWR) (Plastol 6400) and air-entraining

admixture (AEA) (Airex-L).

Table 5.1: Chemical and Physical Properties of Cement and SF

Chemical Composition and

Physical Properties

Cement SF

GU HS HE GUL

CaCO3 (%) 2.5 0.0 3.5 11.9 ---

SiO2 (%) 19.6 21.6 19.1 18.2 92.1

Al2O3 (%) 5.2 4.0 5.2 5.0 0.3

Fe2O3 (%) 2.3 4.3 2.4 2.3 0.6

CaO (%) 61.8 65.6 61.6 61.0 0.8

MgO (%) 2.4 1.1 2.4 2.2 0.7

SO3 (%) 4.00 2.1 4.3 4.0 0.2

Na2Oeq (%) 1.02 0.60 1.0 0.9 0.9

C3S (%) 44.9 64.0 55.2 61.9 ---

C3A (%) 10.3 3.0 9.8 9.4 ---

C4AF (%) 7.0 13.0 7.1 6.9 ---

C2S (%) 22.3 14.0 13.2 5.4 ---

LOI at 1150 °C (%) 2.61 0.40 2.1 5.8 2.0

Blaine (m2/kg) 417 401 514 490 ---

121



17µm 3µm

LOI at 1050°C (%) 42.8 42.4

CaCO3 (%) 95.0 96.0

MgCO3 (%) 2.0 2.0

% Retained on 44μm mesh 15.000 0.003

Blaine (m2/kg) 475 1125


5.2.2. Mix Design

The details for ten SCC mix designs containing 5% SF and designed to achieve a minimum

compressive strength of 44 MPa in 16 hours are given in Table 5.3. All concrete mixes had

a w/c ratio of 0.34. The total cementing material content was 450 kg/m3. LF was used to

replace 15% of cement by weight. CSA A23.1-14 requires 6 to 9% fresh air content for

concrete with a maximum aggregate size of 10 mm and 5% to 8% for concrete with a

maximum aggregate size of 14 to 20 mm. Since the maximum aggregate size used in this

thesis was 13 mm, the fresh air content in all concrete mixes was set to 5%. The concrete

mixture made with GUL cement (which had 11.9% interground limestone) was used

without any additional blended LF to represent the commercially available GUL in Canada.

Limestone (blended or interground) was not considered as a cementitious material in w/c

ratio calculation. All concrete mixes had a coarse aggregate content of 900 kg/m3. Concrete

mixing was done in a 30-litre drum mixer. Each concrete mix design was prepared in two

batches of 30 litres. SCC mixes were prepared by blending coarse aggregate and sand with

80% of water for 1 minute followed by the addition of cement and the remaining 20% of

water containing AEA and mixing for 3 minutes. Following that, HRWR was added and

the concrete was mixed for an additional 4 minutes.

122

Table 5.3: Weight Proportions of Concrete Mixes

Mix ID Cement SF

Coarse

Agg. Water

LF Sand/Agg.

Ratio

AEA HRWR Size

(μm) kg/m3

kg/m3 ml/100kg

GU 427.5 22.5 950 150.3 --- --- 0.47 37 900

GU-17µm 360 22.5 950 123.0 17 67.5 0.47 120 2300

GU-3µm 360 22.5 950 123.0 3 67.5 0.47 148 2450

HE 427.5 22.5 950 150.3 --- --- 0.47 45 1000

HE-17µm 360 22.5 950 123.0 17 67.5 0.47 195 2350

HE-3µm 360 22.5 950 123.0 3 67.5 0.47 240 2500

GUL 427.5 22.5 950 126.0 --- --- 0.47 190 2400

HS 427.5 22.5 950 150.3 --- --- 0.47 25 500

HS-17µm 360 22.5 950 121.0 17 67.5 0.47 60 1900

HS-3µm 360 22.5 950 121.0 3 67.5 0.47 70 2000


Concrete was moist cured at 23°C for two hours (preset period) prior to steam curing. The

selection of 2 hours preset period was based on the initial setting time testing on cement

pastes according to ASTM C191 which showed the initial setting time of 77-94 minutes.

The initial setting time of paste is expected to correlate to the initial setting time of concrete

since paste is the active ingredient in concrete causing the setting. Three steam curing

regimes were used, namely Regime 1, 2 and 3, as presented in Figure 5.1. The maximum

curing temperature was 55°C in Regime 1, 70°C in Regime 2 and 82°C in Regime 3. All

regimes had a heating and cooling rate of`16 °C/hour and a total duration of 16 hours. The

temperature of the chamber was controlled to maintain the required internal temperature of

the samples using Type T thermocouples. The relative humidity was controlled by a steam

generator built into the environmental chamber. After steam curing, concrete cylinders

used in the mechanical properties testing were moist cured at 23°C and 100% RH until

testing. Concrete prisms used in concrete expansion testing were immersed in water at

23°C for 300 days. The use of water instead of limewater was to promote the leaching of

alkali [32]. The reason for curing the concrete cylinders in 100% RH instead of water

immersion (as in concrete expansion prisms) was to extend the results obtained from

Chapter 4 in which all concrete cylinders were moist cured at 100% RH. Furthermore, it

has been reported that immersing concrete in water or exposing to 100% RH have similar

effects in promoting the expansion due to DEF [33]

123


5.2.4. Testing Methods

Fresh Properties:

Unlike the comprehensive testing of fresh properties conducted in Chapter 4, the fresh

properties testing in this chapter was limited to slump flow and Visual Stability Index (VSI)

in accordance with ASTM C1611-14 and fresh air content using a type-B meter in

accordance with ASTM C231-10.

Air Void Analysis of Hardened Concrete:

Three mix designs were selected for air void analysis, mix GU-17µm, HE and HE-17µm.

The concrete specimens used in this test was 100 mm in width × 120 mm in length. The

polished concrete samples were scanned using high-resolution flatbed scanner and the

analysis was conducted using a computer software (ImageJ with air void analysis script)

[34].

Mechanical Properties:

The mechanical properties of concrete were evaluated using compressive strength and UPV

tests at 16 hours and at 28 and 300 days. At each age, three samples were tested for

compressive strength and UPV and the average value was reported. The compressive

strength testing was measured in accordance with CSA A23.2-9C on samples with 200 mm

10

20

30

40

50

60

70

80

90

0 2 4 6 8 10 12 14 16 18

Tem

per

ature

(°C

)

Steam Curing Duration (hour)

Curing Regime Actual Concrete Temperature

Regime 1

10.0 hours at 55°C

Regime 2

8.1 hours at 70°C

Regime 3

6.6 hours at 82°C

95% RH

124

height × 100 mm diameter [35]. The UPV was measured in accordance with ASTM C597-

09.

Transport Properties:

The transport properties were evaluated using RCPT at 28 and 300 days in accordance with

ASTM C1202-10.

Concrete Expansion:

The concrete expansion was measured using concrete prisms with 50 mm width × 50 mm

depth × 285 mm length in accordance with ASTM C 490-11. Following steam curing,

concrete prisms were immersed in water at 23°C. The initial reading was taken

immediately at the end of steam curing and every 14 days thereafter until 300 days.

Scanning Electron Microscopy:

At the end of 300 days of water immersion, the microstructure analysis of concrete mixes

was evaluated using SEM with a backscattered electron detector on fracture surface. In

addition to the fracture surface analysis, thin-section was prepared for microstructure

analysis of concrete. The thin-sections were cut perpendicular to the strong axis of the

concrete prims at approximately 10 to 20 mm from the edge of the prism. Since one prism

from each mix was selected for the microstructure analysis, caution was taken to avoid the

locations where the fracture surface samples were extracted.

Freeze-Thaw Resistance:

After immersion in water for 300 days, the concrete prisms used in the expansion

measurements were tested for freeze-thaw resistance in accordance with ASTM C666-15.


5.3.1. Fresh Properties

The fresh properties of concrete are presented in Table 5.4. All concrete mix designs had a

fresh air content ranging from 4.9% to 5.7%, a slump flow of 660 ± 30 mm and VSI ranging

from 0 to 0.5. The plastic properties of all concrete mixes fell within the required ranges

based on CSA A23.1-14.

125

Table 5.4: Plastic Properties of Concrete

Mix ID Plastic Air Content (%) Slump

Flow (mm) VSI

GU 5.2 690 0.5

GU-17µm 5.3 640 0

GU-3µm 5.0 655 0

HE 5.4 660 0.5

HE-17µm 4.9 645 0

HE-3µm 5.2 650 0

GUL 5.7 695 0.5

HS 4.9 630 0.5

HS-17µm 5.3 685 0

HS-3µm 5.0 645 0

5.3.2. Air Void Analysis of Hardened Concrete

The results of the air void analysis of hardened concrete are presented in Table 5.5. Three

mix designs were selected, mix GU-17µm, HE and HE-17µm. This table shows that the

hardened air content was within ±0.3 of the air content measured in fresh concrete. The

spacing factor ranged from 0.138 mm to 0.177 mm while the air void specific surface

ranged from 28.19 mm-1 to 33.79 mm-1. The spacing factor of the tested concrete was below

the required value of 0.20 mm set by ASTM C-457-12.

Table 5.5: Results of Air Void Analysis of Hardened Concrete

Mix ID Fresh Air

Content (%)

Air Void Analysis of Hardened Concrete

Calculated Air

Content (%)

Specific Surface

(mm-1)

Spacing Factor

(mm)

GU-17µm 5.3 5.0 28.19 0.177

HE 5.4 5.7 33.79 0.138

HE-17µm 4.9 4.8 32.40 0.157

5.3.3. Compressive Strength

The results of the compressive strength are presented in Figures 5.2, 5.3 and 5.4 (please

refer to Section A.7.3 in Appendix A for the raw data and the statistical analysis). In Figures

5.2, 5.3 and 5.4, the minimum value for the compressive strength axis was set to 44 MPa

which is the required 16-hour compressive strength. Figure 5.2 presents the compressive

strength of concrete mixes steam cured at 55°C while Figures 5.3 and 5.4 present the

126

compressive strength of concrete mixes which were steam cured at 70°C and 82°C,

respectively. Each column in the figure is the average of three samples.

As would be expected, concrete mixes made with HE cement achieved greater 16-hour

compressive strength compared to concrete mixes made with GU cement. However, the

greater 16-hour compressive strength in HE cement mixes compared to GU cement mixes

was only observed at a steam curing temperature of 55°C, as presented in Figure 5.2. When

the steam curing temperature increased to 70°C and 82°C, the 16-hour compressive

strength of concrete mixes made with HE and GU cement was similar, as presented in

Figures 5.3 and 5.4. At 28 days, concrete mixes made of HE and GU cement had similar

compressive strength regardless of steam curing temperature. At 300 days, concrete mixes

made with HE cement had 2% to 6% lower compressive strength compared to concrete

mixes made with GU cement regardless of steam curing temperature.

When the fineness of LF was greater than the fineness of the cement, the addition of LF

increased the 16-hour compressive strength of concrete steam cured at 55°C, as presented

in Figure 5.2. For example, concrete mixture made of GU cement and 17µm LF showed

4% increase in the 16-hour compressive strength compared to the control mixture without

LF. When the LF size was reduced from 17µm to 3µm (i.e., Blaine fineness of LF increased

from 475 m2/kg to 1125 m2/kg) the percentage increase in the 16-hour compressive strength

was 15% compared to the control mixture made of GU without LF. On the other hand,

concrete mixture made of HE cement and 17µm LF showed 4% less 16-hour compressive

strength compared to the control mixture made with HE cement without LF. The lower 16-

hour compressive strength in concrete mixture made with 17µm could be due to the lower

fineness of LF (i.e., 475 m2/kg) compared to HE cement (i.e., 514 m2/kg). Reducing LF

size from 17µm to 3µm increased the 16-hour compressive strength by 3% compared to

the control mixture made with HE cement without LF. At 28 days, concrete mixes made

with GU and HE cement with and without LF had similar compressive strength regardless

of steam curing temperature, as presented in Figures 5.2, 5.3 and 5.4. However, at 300

days, concrete mixes made with LF had 3% to 5% less compressive strength compared to

concrete mixes made without LF. The lower strength in concrete mixes made with LF

compared to concrete mixes made without LF was due to the dilution effect.

127

The concrete mixture which was made with GUL cement and steam cured at 55°C had

similar 16-hour compressive strength compared to the concrete mixture made with blended

GU cement with 3µm LF, as presented in Figure 5.2. However, when the steam curing

temperature was increased from 55°C to 70°C and 82°C, the compressive strength of GUL

mixture was 4% less compared to the concrete mixture made with blended GU cement with

3µm LF, as presented in Figures 5.3 and 5.4. At 28 and 300 days, all concrete mixes made

with GUL cement and blended GU cement with LF (17µm and 3µm) had similar

compressive strength. The change in the chemical composition in GU and HS cement did

not cause any significant effect on the compressive strength. The percentage difference in

the compressive strength between concrete mixes made with GU and HS cements was

within ± 5% regardless of age or steam curing temperature.

The results showed that the steam curing temperature has the greatest influence on the

compressive strength evolution. Increasing steam curing temperature caused a significant

increase in the 16-hour compressive strength, as presented in Figure 5.5. In this figure,

logarithmic regression lines are used to present the evolution of compressive strength at

steam curing temperature of 55°C, 70°C and 82°C. The increase in the steam curing

temperature from 55°C to 70°C and 82°C increased the 16-hour compressive strength by

approximately 12% and 25%, respectively. However, the gain in the compressive strength

in concrete mixes that were steam cured at 70°C and 82°C diminished with time. At 28

days, the compressive strength of concrete mixes steam cured at 55°C, 70°C and 82°C were

approximately the same (70 MPa to 74 MPa). At 300 days, concrete mixes steam cured at

70°C and 82°C had approximately 8% lower compressive strength compared to those cured

at 55°C.

128

Figure 5.2: Effect of Mixing Proportion on the Compressive Strength of Concrete Mixes

Cured at 55°C


Cured at 70°C

44

50

56

62

68

74

80

86

92

0.67 28 300

Co

mp

ress

ive

Str

ength

(M

Pa)

Age (Days)


GUL HS HS-17µm HS-3µm 1

16 hours

44

50

56

62

68

74

80

86

92

0.67 28 300

Co

mp

ress

ive

Str

ength

(M

Pa)

Age (Days)



16 hours

129


Cured at 82°C

Figure 5.5: Effect of Steam Curing Temperature on the Evolution of Compressive

Strength

44

50

56

62

68

74

80

86

92

0.67 28 300

Co

mp

ress

ive

Str

ength

(M

Pa)

Age (Days)



16 hours

45

50

55

60

65

70

75

80

85

90

0.1 1.0 10.0 100.0 1000.0

Co

mp

ress

ive

Str

ength

(M

Pa)

Age (Days)-Log Scale

55°C 70°C 82°C

Log. (55°C) Log. (70°C) Log. (82°C)

Steam Curing Temperature:

16 hrs. 28 300

82°C

70°C

55°C

130

5.3.4. Ultrasonic Pulse Velocity

The uniformity, density and homogeneity of concrete were assessed using UPV test. Based

on the UPV values, the quality of concrete can be classified as excellent, good or doubtful.

Concrete with excellent quality has a UPV value above 4500 m/s while concrete with good

and doubtful quality has a UPV values between 3500 m/s to 4500 m/s and 3000 m/s to

3500 m/s, respectively [36]. The values of the UPV are presented in Table 5.6. Each UPV

value is the average of three tests and the coefficient of variation was below 4% (please

refer to Section A.7.3 in Appendix A for the raw data and the statistical analysis). All

concrete mixes had a UPV equal or greater than 4500 m/s and therefore considered with

excellent quality. At 16 hours, concrete mixes made with HE cement and steam cured at

55°C had 4% to 11% greater UPV compared to similar mixes made with GU cement.

However, this gain in the UPV in concrete mixes made with HE cement diminished with

time. At 28 and 300 days, concrete mixes which were steam cured at 55°C and made with

GU and HE cement had similar UPV values. No significant effect of LF was observed on

the UPV values regardless of the cement type, curing age or steam curing temperature. The

concrete mixture which was made of GUL cement had similar UPV values compared to

concrete mixes made of GU cement blended with LF (17µm and 3µm) at all ages regardless

of steam curing temperature. Concrete mixes steam cured at 70°C and 82°C had greater

UPV values at 16 hours compared to similar concrete mixes steam cured at 55°C. At 28

and 300 days, no effect of steam curing was observed on the UPV values. The change in

the chemical composition of cement in GU and HS cement did not cause any significant

effect on the UPV values. At any given age, the percentage difference in the UPV values

between concrete mixes made of GU and HS cements were within ± 5% regardless of the

presence of LF, curing duration or steam curing temperature.

131

Table 5.6: UPV Values of Concrete Steam Cured at 55°C, 70°C and 82°C

Mix ID Steam Curing

Temperature

Ultrasonic Pulse Velocity

(m/s)

16 hours 28 days 300 days

GU

55°C

4480 5104 5330

GU-17µm 4701 5080 5412

GU-3µm 4720 5180 5475

HE 4920 5130 5290

HE-17µm 4987 5105 5218

HE-3µm 5000 5138 5285

GUL 4693 5050 5320

HS 4734 5019 5395

HS-17µm 4675 5015 5214

HS-3µm 4592 4950 5193

GU

70°C

4639 5038 5330

GU-17µm 4702 5102 5330

GU-3µm 4702 4975 5330

HE 4702 4963 5193

HE-17µm 4680 4975 5156

HE-3µm 4700 4901 5224

GUL 4752 4980 5301

HS 4533 4995 5348

HS-17µm 4489 4987 5324

HS-3µm 4424 4890 5208

GU

82°C

4734 5000 5358

GU-17µm 4802 5064 5401

GU-3µm 4901 5142 5474

HE 4707 5012 5193

HE-17µm 4802 5000 5290

HE-3µm 4792 4987 5239

GUL 4714 5000 5286

HS 4587 4974 5193

HS-17µm 4612 4857 5189

HS-3µm 4662 4872 5235

132

5.3.5. Rapid Chloride Permeability

The RCPT values are presented in Figures 5.6 and 5.7. Figure 5.6 presents the RCPT values

at 28 days while Figure 5.7 presents the RCPT values at 300 days (please refer to Section

A.7.4 in Appendix A for the raw data and the statistical analysis). Each column in the

figures is the average of three sample whereas the confident of variation was less than 8%.

The coefficient of variation of the RCPT values was higher compared to the compressive

strength and the UPV tests. However, the coefficient of variation of the RCPT values were

below the 42% limit set by ASTM C1202.

In general, all concrete mixes showed RCPT values from 300 to 1400 Coulombs at 28

days and from 200 to 1000 Coulombs at 300 days. According to the Ontario Provincial

Standard Specification OPSS 909 (for prestressed concrete) and OPSS999 (for non-

prestressed concrete), the maximum allowable RCPT value for concrete containing SF is

1000 Coulombs at 28 days. From Figure 5.6, all concrete mixes steam cured at 55°C had

RCPT values lower than 1000 Coulombs. For concrete mixes steam cured at 70°C, all

mixes were approximately around the OPSS limit of 1000 Coulombs except for concrete

mixes made of GUL and HS cements. Concrete mixes which were steam cured at 82°C

had RCPT values greater than 1000 Coulombs except for mix GU-3µm.

The RCPT values of concrete mixes made of HE cement and steam cured at 55°C were

12% to 23% less compared to concrete mixes made with GU cement at 28 and 300 days,

respectively. However, when the steam curing temperature increased from 55°C to 70°C

and 82°C, the RCPT values of concrete mixes made of HE and GU cement were similar at

28 and 300 days.

The addition of LF reduced the RCPT values of concrete compared to concrete mixes made

without LF regardless of curing duration or steam curing temperature. Concrete mixes

made with LF of 3µm had lower RCPT compared to concrete mixes made with 17µm LF.

At 28 days, concrete mixture made with GUL cement had greater RCPT value compared

to concrete mixes made of GU cement blended with 17µm and 3µm LF. At 300 days,

concrete mixture made with GUL cement and concrete mixes made of GU cement blended

with LF had approximately the same RCPT values regardless of steam curing temperature.

At 28 days, concrete mixes made of GU and HS cements had similar RCPT values when

steam cured at 55°C. However, concrete mixes made of HS cement had greater RCPT

133

values compared mixes made of GU cement when steam cured at 70°C and 82°C. At 300

days, concrete mixes made of GU and HS cement had similar RCPT values regardless of

the steam curing temperature.

The steam curing temperature was the most influential variable on RCPT values. Increasing

steam curing temperature from 55°C to 70°C increased the RCPT values by approximately

100% compared to concrete mixes steam cured at 55°C. Further increase in the steam

curing temperature from 70°C to 82°C increased the RCPT values by approximately 124%

compared to concrete mixes steam cured at 55°C. The higher RCPT values in concrete

mixes steam cured at 70°C and 82°C was caused by the higher hydration rate compared to

concrete steam cured at 55°C, which increases the non-uniformity of the hydration products

causing higher concrete permeability [37,38].

Figure 5.6: Effect of Steam Curing Temperature on the RCPT Values of Concrete at 28

Days

0

200

400

600

800

1000

1200

1400

1600

55°C 70°C 82°C

RC

PT

(C

oulo

mb

s)

Steam Curing Temperature



OPSS 909 Limit

134

Figure 5.7: Effect of Steam Curing Temperature on the RCPT Values of Concrete at 300

Days

5.3.6. Concrete Expansion

The final expansions of concrete mixes after immersion in water for 300 days are presented

in Figure 5.8. The expansion curves of all concrete mixes are presented in Section A.7.5.1

in Appendix A. The expansion curves in Section A.7.5.1 in Appendix A showed higher

initial expansion in the first two weeks of water immersion. This is due to the water intake

causing the swelling of the concrete prisms. However, this expansion is an integral part of

the total expansion that concrete can accommodate before cracking. Furthermore, the

precast/prestressed concrete elements are expected to expand due to the water intake if

exposed to wet environment (the wet environment is also a necessity for DEF expansion).

In addition, by analyzing the expansion curves, the increase in the expansion due to the

increase in steam curing temperature was not influenced by the initial swelling due to the

water intake. Therefore, no correction was made on the concrete expansion to account for

the initial swelling due to the water intake. Visual examination of concrete prisms did not

reveal any visible cracking. The expansions were below 0.05% (expansion at which

concrete starts to crack) after 300 days of immersion in water. When the concrete was

steam cured at 55°C, the expansion of all concrete mixes was below 0.021%. However,

0

400

800

1200

1600

55°C 70°C 82°C

RC

PT

(C

oulo

mb

s)




135

when the steam curing temperature increased from 55°C to 70°C and 82°C, the expansion

of concrete mixes made of GU, HE and GUL was significantly increased, as presented in

Figure 5.8.

Figure 5.8: Effect of Steam Curing Temperature on Concrete Expansion after 300 Days

of Water Immersion

Concrete mixes steam cured at 55°C and made with GU and HE cement had similar

expansion (0.01% after 300 days). However, when the steam curing temperature increased

from 55°C to 70°C and 82°C, concrete mixes made with HE cement had lower expansion

compared to concrete mixes made with GU cement. LF did not influence the expansion of

concrete mixes made of GU and HE cement when the concrete was steam cured at 55°C,

as presented in Figures 5.8. However, LF slightly reduced the expansion of concrete mixes

made of GU and HE cement when the concrete was steam cured at 70°C and 82°C. The

reduction in the concrete expansion with 17µm and 3µm LF was similar in concrete mixes

made with LF compared to the control mixes made of GU and HE cement without LF. This

reduction in the concrete expansion when cement was replaced by LF was due to the

0.000

0.010

0.020

0.030

0.040

0.050

Concr

ete

Ex

pan

sion

at

300 D

ays

(%)

82°C 70°C 55°C Series4Steam curing Temperature:

GU HE HS

Mix ID

136

reduction in cement content, which reduces the amount of DEF that could form in the

system and thus reduces the expansion of the concrete. In addition, concrete mixes made

with LF had lower permeability compared to concrete mixes made without LF. The lower

permeability of concrete restricts the mobility of water and thus reduces the expansion. To

prove this, Figure 5.9 present the relationship between concrete expansion and RCPT

values at 300 days. This figure shows a strong correlation between concrete expansion and

RCPT values.

Figure 5.9: Relationship between Concrete Expansion and RCPT Values in Mixes Made

of GU, HE and GUL at 300 Days

The concrete mixture made with GUL cement showed similar expansion compared to

concrete mixes made of GU cement blended with 17µm and 3µm LF at a steam curing

temperature of 55°C. However, when the steam curing temperature increased to 70°C and

82°C, GUL concrete mixture showed lower expansion compared to concrete mixes made

with GU cement blended with LF of 17µm and 3µm. Concrete mixes which were made of

HS cement and steam cured at 55°C had similar expansion compared to mixes made of GU

cement (approximately 0.015%). However, when the steam curing temperature increased

to 70°C and 82°C the expansions of concrete mixes made of HS cement were significantly

less compared to concrete mixes made of GU cement. After 300 days, the expansions of

concrete mixes steam cured at 70°C and 82°C and made of HS cement was below 0.021%

R² = 0.82

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0 200 400 600 800 1000 1200 1400

Co

ncr

ete

Exp

ansi

on a

fter

30

0 D

ays

RCPT Values at 300 Days (Coulombs)

137

whereas the expansions in concrete mixes made of GU cement was approximately 0.037%

at 70°C and 0.042% at 82°C. The reduction in the concrete expansion when the HS cement

was used was due to the lower sulfate and alkali contents compared to GU cement which

means less produced DEF in HS cement mixes compared to GU cement mixes.

Steam curing temperature had a significant effect on the expansion of concrete made of

GU, HE and GUL cements. The increase in the expansion in concrete mixes steam cured

at 70°C and 82°C was 156% and 166%, respectively, compared to concrete mixes steam

cured at 55°C. It was also observed that a significant increase in concrete expansion occurs

when the steam curing temperature increased from 55°C to 70°C. However, there was no

significant increase in the concrete expansion when the steam curing temperature was

increased from 70°C to 82°C.

Concrete expansion did not cause any loss in the mechanical properties of concrete steam

cured at 70°C and 82°C after 300 days of water immersion. This might be due to the lower

level of expansion (maximum expansion was below 0.045%) observed in the concrete,

which agrees with the observations from other research studies [15,16,39].

The concrete expansion was reduced with the use of HE cement (instead of GU), the use

of LF and the use of GUL cement (instead of blended GU cement with 17µm and 3µm

LF). However, this reduction was insignificant compared to the reduction that could be

achieved by reducing the steam curing temperature or reducing the sulfate and alkali

contents in the cement. The expansion of concrete mixes made of HS cement was

significantly low compared to the expansion of concrete mixes made of GU, HE and GUL

cements when steam cured at 70°C and 82°C. This suggests that the expansion in GU, HE

and GUL cement mixes when steam cured at 70°C and 82°C was due to DEF. However,

this theory will be examined by microstructural analysis using SEM.

5.3.7. Scanning Electron Microscopy

At the end of 300-day immersion in water, a microstructural analysis of concrete mixes

was carried out using SEM with a backscattered electron detector on fracture surface and

thin-sections. The SEM images revealed that concrete mixes which were made of GU, HE

and GUL cements and steam cured at 70°C and 82°C had secondary ettringite and calcium

hydroxide crystals in the air voids. Figures 5.10 and 5.11 present SEM images of fracture

surface of concrete steam cured at 70°C and 82°C, respectively, taken at the edge of the

138

concrete prisms. It was also observed that the air voids closer to the surface were more

filled with secondary ettringite. On the other hand, no traces of secondary ettringite

formation was observed in concrete mixes steam cured at 55°C, as presented in Figure

5.12. Figure 5.12 presents SEM images of concrete mixes steam cured at 55°C. The SEM

microstructural analysis showed no differences between concrete mixes made with and

without LF. Air voids in concrete mixes which were steam cured at 82°C had more

secondary ettringite in air voids compared to concrete mixes steam cured at 70°C.

Figure 5.10: Fracture Surface SEM (Backscattered Electron) Images of Concrete Steam

Cured at 70°C Showing Secondary Ettringite and Calcium Hydroxide (CH) Crystals

Growing in Air Voids (a) GU, (b) HE, (c) GU-3µm and (d) HE-17µm

139


Cured at 82°C Showing Secondary Ettringite and Calcium Hydroxide (CH) Crystals

Forming in Air Voids (a) GU, (b) GU-17µm, (c) GU-3µm, (d) GUL

Concrete mixes made of HS cement showed no secondary ettringite in air voids when

steam cured at 55°C and 70°C. Nevertheless, secondary ettringite formation was observed

in concrete mixes made of HS cement and steam cured at 82°C, as presented in Figure

5.13. However, this secondary ettringite formation in air voids was significantly less

compared to similar concrete mixes made of GU, HE and GUL cements.

140


Cured at 55°C Showing Empty Air Voids (a) GU, (b) GU-3µm, (c) HS-3µm and (d) HE

Figure 5.13: Fracture Surface SEM (Backscattered Electron) Image of Concrete Mixture

HS-3µm-82°C Showing Minor Secondary Ettringite Formation in Air Void

141

The SEM analysis using thin-sections showed that concrete mixes steam cured at 82°C had

microcracks, as shown in Figure 5.14 for mix GU-17µm (please refer to Section A.7.6 in

Appendix A for the locations of the SEM images in the thin-section and for additional SEM

images). Narrow empty gaps were observed partially surrounding or in some cases fully

surrounding the sand particles, as presented in Figure 5.15. Ettringite deposits were found

in the interfacial transition zone, as presented in Figure 5.16. The ettringite deposits in the

interfacial transition zones and the narrow gaps surrounding the sand particles are typical

signs of expansion due to DEF [22,40]. No microcracks were observed in concrete mixes

steam cured at 55°C and 70°C except for mix GU-70°C, as presented in Figure 5.17. In

mix GU-70°C, the microstructural analysis showed some microcracks. However, these

microcracks were smaller and less connected compared to the same mix steam cured at

82°C, as presented in Figure 5.18. In addition, concrete mixes made of HS cement showed

no microcracks when steam cured at 82°C, as presented in Figure 5.19.

To further assess the influence of LF and steam curing temperature, the distribution of the

secondary ettringite formation was evaluated. For this analysis, four concrete mix designs

were selected, namely GU-82°C, GU-3µm-70°C, GU-3µm-82°C and HS-3µm-82°C. At

10 mm from the edge of the concrete prisms, a cross-section was made. In this cross-

sectional area, the air voids smaller or equal to 200µm in diameter were analyzed. The air

voids were categorized into three categories based on the level of secondary ettringite

formation in the air voids. The first category (Category 1) consisted of air voids that had

minor or no secondary ettringite formation. The second category (Category 2) consisted of

air voids with major secondary ettringite formation but the volume of the air voids was not

completely compromised. The third category (Category 3) consisted of air voids that were

completely filled with secondary ettringite formation. Figure 5.20 presents the secondary

ettringite distribution in mix GU-82°C, GU-3µm-70°C, GU-3µm-82°C and HS-3µm-

82°C. From this figure, it can be observed that the secondary ettringite was mainly

concentrated at the corners of the (50 mm × 50 mm) concrete cross-section. By comparing

Figure 5.20 (a) to (b) it was observed that the addition of LF reduced the secondary

ettringite formation in air voids. However, steam curing temperature seems to have a

greater effect on the secondary ettringite distribution. It can be observed from Figure 5.20

(b) and (c) that the secondary ettringite formation was less aggressive in mix GU-3µm-

70°C compared to GU-3µm-82°C. Figure 5.20 (d) showed minor ettringite formation in air

142

voids at the corner of the concrete cross-section. The secondary ettringite distribution

analysis results showed that the steam curing temperature and the chemical composition of

the cement were the most influential variables on the distribution of secondary ettringite.

This agrees with the findings obtained from concrete expansion results and the

microanalysis of the fracture surface.

Figure 5.14: SEM (Backscattered Electron) Images of Concrete Thin-Section Showing

Microcracks and Secondary Ettringite Filling Smaller Air Voids (Mix GU-17µm-82°C)

Microcrack

Air Voids

Filled with

Secondary

Ettringite

0

500

1000

1500

2000

0 2 4 6

Coun

ts

KeV

Ca

Ca

S

Al

O

143

Figure 5.15: SEM (Backscattered Electron) Images of Concrete (GU-17µm-82°C)

Showing Narrow Empty Gaps Surrounding Sand Particles

Figure 5.16: SEM (Backscattered Electron) Images of Concrete (GU-17µm-82°C)

Showing Ettringite Deposits (Circles) Found in the Interfacial Transition Zone

144

Figure 5.17: SEM (Backscattered Electron) Images of Concrete (a) GU-17µm-55°C and

(b) GU-17µm-70°C

145

Figure 5.18: SEM (Backscattered Electron) Images of Concrete Showing Microcracks

(circles) (a) GU-70°C and (b) GU-82°C

(a)

(b)

146

Figure 5.19: SEM (Backscattered Electron) Images of Concrete (Mix HS-17µm-82°C)

The ettringite distribution presented in Figure 5.20 shows that at 10 mm from the edge of

the concrete prisms, the center of the prisms did not have any significant formation of

secondary ettringite in air voids. The availability of moisture close to the surface of

concrete had two roles in increasing the secondary ettringite formation in air voids. Firstly,

the formation of ettringite requires the presence of moisture and therefore, ettringite

formation was greater in areas close to the surface of the concrete. Secondary, the leaching

of alkali will be greater in areas close to the surface of the concrete.

147

Figure 5.20: Secondary Ettringite Distribution in Air Voids in a Cross-section

(50×50mm) of Concrete (a) GU-82°C, (b) GU-3µm -82°C, (c) GU-3µm-70°C and (d)

HS-3µm-82°C

25 20 15 10 -5 5 10 15 20 25

253 3 3 3 3 3 3 3 3 3

203 3 3 2 2 2 3 3 3 3

153 3 3 2 2 2 2 2 3 3

103 3 2 2 2 2 1 2 3 3

53 2 2 2 1 1 2 2 2 3

-53 2 2 2 1 1 1 2 2 3

-103 3 2 2 1 1 2 3 3 3

-153 3 3 2 2 1 2 2 3 3

-203 3 3 2 2 2 2 3 3 3

-253 3 3 3 3 3 3 3 3 3

25 20 15 10 -5 5 10 15 20 25

253 3 3 3 2 3 3 3 3 3

203 3 3 2 2 2 2 3 3 3

153 3 2 1 2 2 2 2 3 3

103 2 2 1 1 1 1 2 2 3

52 2 2 1 1 1 2 2 2 3

-52 2 2 1 1 1 1 2 2 3

-103 2 2 2 1 1 2 2 3 3

-153 3 2 2 2 1 2 2 2 3

-203 3 3 2 2 2 2 3 3 3

-253 3 3 3 3 3 3 3 3 3

25 20 15 10 -5 5 10 15 20 25

252 2 2 1 1 2 1 1 2 2

202 1 1 1 1 1 1 1 1 2

152 1 1 1 1 1 1 1 1 1

101 1 1 1 1 1 1 1 1 1

51 1 1 1 1 1 1 1 1 1

-51 1 1 1 1 1 1 1 1 1

-102 1 1 1 1 1 1 1 1 1

-151 1 1 1 1 1 1 1 1 1

-201 1 1 1 1 1 1 2 1 2

-252 2 1 1 1 1 1 1 2 2

25 20 15 10 -5 5 10 15 20 25

253 3 3 3 2 2 3 3 3 3

203 3 2 2 2 2 2 2 3 3

153 2 2 1 1 2 1 2 2 3

103 2 2 1 1 1 1 2 2 3

52 2 1 1 1 1 2 1 2 2

-52 2 2 1 1 1 1 2 2 2

-103 2 1 1 1 1 2 2 2 3

-153 2 2 2 2 1 2 2 2 3

-203 3 2 2 2 2 2 3 3 3

-253 3 3 3 2 3 3 3 3 3

Distance (mm) D

ista

nce

(m

m)

Category 1: air voids have minor or no secondary ettringite formation

Category 3: air voids are completely filled with secondary ettringite formation

Category 2: air voids have major secondary ettringite formation but the volume of air voids is not

completely compromised

(a) (b)

(c) (d)

148

5.3.8. Freeze-Thaw Resistance

At the end of 300 days, the freeze-thaw testing was carried out on the concrete prisms used

in expansion measurements. The durability factor of concrete mixes after 300 cycles of

freeze-thaw is presented in Figure 5.21 (please refer to Section A.7.5 in Appendix A for

the raw data and the statistical analysis). Concrete mixes steam cured at 55°C had a

durability factor greater than 96% regardless of the cement type or the presence of LF.

However, when the steam curing temperature increased from 55°C to 70°C and 82°C, the

durability factor of concrete mixes made of GU, HE and GUL cements was significantly

reduced.

Figure 5.21: Effect of Steam Curing Temperature on Durability Factor of Concrete

Concrete mixes which were made with HE cement and steam cured at 70°C had 4% to 19%

greater durability factor compared to concrete mixes made with GU cement. When the

steam curing temperature increased to 82°C, all concrete mixes made with HE and GU

cement had similar durability factors. The addition of LF increased the durability factor of

concrete. This increase in the durability factor with the addition of LF was statistically

significant in concrete mixes made of GU and HE cement and steam cured at 82°C. At

steam curing temperature of 70°C, only concrete mixes made of GU cement showed

40

50

60

70

80

90

100

Dura

bil

ity F

acto

r (%

)

55°C 70°C 82°C Series4

CSALimit

Steam curing Temperature:

GU HE HS

Mix ID

149

statistically significant increase in the durability factor with the addition of LF. Concrete

mixes made with 17µm and 3µm LF had similar durability factor regardless of the cement

type or the steam curing temperature. The concrete mixture made of GUL cement had

similar durability factor compared to concrete mixes made of blended GU cement with

17µm and 3µm LF regardless of the steam curing temperature. Concrete mixes made of

HS cement had a durability factor greater than 92% regardless of the steam curing

temperature.

The loss in the durability factor with the use of GU, HE and GUL cements at the higher

steam curing temperature (i.e., 70°C and 82°C) was due to three factors. Firstly, concrete

mixes steam cured at 82°C except mixes made with HS cement had developed microcracks

at the end of the 300 days of water immersion. Secondly, concrete mixes made of GU, HE

and GUL cements and steam cured at 70°C and 82°C were under greater tensile stress due

to the greater expansion compared to similar mixes steam cured at 55°C. This might reduce

the additional stress due to freeze-thaw cycles that these mixes (i.e., GU, HE and GUL

mixes steam cured at 70°C and 82°C) can accommodate before cracking. Thirdly, concrete

mixes made of GU, HE and GUL cements showed secondary ettringite formation in air

voids when steam cured at 70°C and 82°C. The secondary ettringite formation in air voids

may occupy some of the space that accommodates the expansion of water under freezing

condition. Detwiler and Powers (1999) have reported that the filling of air voids with

secondary ettringite formation does not contribute to the damage due to freeze-thaw cycles

[41]. However, in their testing, the concrete prisms were moist cured for 3 days only

followed by air curing for 25 days before exposed to freeze-thaw cycles. It is not expected

that enough secondary ettringite formation will be produced during this short period of

time specially that the concrete will be under continuous freeze-thaw cycles. On the other

hand, in this thesis, the secondary ettringite formation was initially exhausted before the

exposure to freeze-thaw cycles. Figure 5.14 showed that the smaller air voids, which are

critical to freeze-thaw resistance, are more filled with secondary ettringite compared to the

bigger air voids. However, Figure 5.20 showed that the distribution of secondary ettringite

in air voids was not uniform and was mainly at the corner and the edge of the concrete

prisms. This might cause the outer side of concrete to have a greater expansion compared

to the inner core as there is less available space to accommodate water expansion. The

difference in expansion level in the outer and inner sides of the concrete creates stresses

150

which might accelerate the deterioration under freeze-thaw cycles. The freeze-thaw cycles

have been reported to promote DEF expansion due to the greater stability of ettringite

compared to monosulfate at freezing temperatures [42]. However, in these studies, the

freeze-thaw cycles were applied at early age. In this thesis, the freeze-thaw cycles were

applied at the end of 300 days at which the ettringite formation is expected to be exhausted.

According to CSA A3004-E1, the minimum allowable durability factor is 80% [43].

Concrete mixes made of HS cement had a durability factor greater than 92% regardless of

the steam curing temperature or the presence of LF. All concrete mixes made of GU, HE

and GUL cements which were steam cured at 55°C had a durability factor greater than

95%. However, when the steam curing temperature increased from 55°C to 70°C, concrete

mixes made with GU, HE and GUL cements had a durability factor that is equal or slightly

greater than 80% except for mix GU where the durability factor was 68%. When the

concrete was steam cured at 82°C, all concrete mixes made of GU, HE and GUL cements

did not pass the limit of 80% (durability factor ranged from 56% to 73%). The reduction

in the freeze-thaw resistance was greater in concrete mixes that exhibited greater

expansion, as presented in Figure 5.22. Steam curing temperature and sulfate and alkali

contents in cement were the most significant variable influencing the freeze-thaw durability

factor. Increasing the steam curing temperature from 55°C to 70°C to 82°C caused

approximately 18% and 30% loss in the durability factor, respectively, compared to

concrete mixes steam cured at 55°C.

151

Figure 5.22: Relationship between Concrete Expansion and Loss in Freeze-Thaw

Durability Factor of Concrete

The results obtained on the effect of LF on concrete expansion due to DEF was in

agreement with the study made by Kurdowski and Duszak [29]. However, it contradicts

the findings made by Silva et al. [30]. In Silva’s study, concrete mixes made of LF had

greater expansions compared to the concrete made without LF. However, the compressive

strength of concrete mixes made with LF was 25% less compared to concrete made without

LF at 28 and 90 days. The lower compressive strength in concrete made with LF causes

the tensile strength of concrete to be lower compared to concrete without LF and thus crack

sooner. In addition, the modulus of elasticity is expected to be lower with lower

compressive strength, which results in greater expansion under the same stress level

compared to concrete with higher elastic modulus [44].

5.4. Conclusions


(i) Limestone filler can increase the 16-hour compressive strength and ultrasonic pulse

velocity of concrete steam cured at 55°C. However, this increase in the 16-hour

compressive strength and ultrasonic pulse velocity diminished when the steam

curing temperature increased from 55°C to 70°C and 82°C.

R² = 0.88

0

0.01

0.02

0.03

0.04

0.05

0.06

0 10 20 30 40 50

Exp

ansi

on a

fter

30

0 D

ays

Loss in F/T Durability Factor (%)

152

(ii) The permeability of concrete was reduced in the presence of limestone filler at 28

and 300 days regardless of steam curing temperature.

(iii) LF slightly reduced the expansion of concrete. This reduction in the concrete

expansion was caused by the reduction in cement content, which reduced the

amount of DEF that could form in the system and thus reduces the expansion. In

addition, the reduced permeability in concrete mixes made with LF might also be a

contributing factor in reducing the expansion.

(iv) The concrete mixture made with GUL had similar hardened properties and

durability performance compared to concrete mixes made of GU cement blended

with 17µm and 3µm LF.

(v) Concrete mixes made with HS cement showed similar compressive strength and

ultrasonic pulse velocity values compared to concrete mixes made with GU cement.

However, concrete mixes made with HS cement showed significantly less

expansion compared to concrete mixes made of GU cement. This is due to the lower

sulfate and alkali contents in HS cement compared to GU cement, which reduces

the expansion due to DEF.

(vi) Concrete mixes made of HS cement showed no significant loss in the freeze-thaw

durability factor regardless of the steam curing temperature. On the other hand,

concrete mixes made of GU, HE and GUL cements showed a significant loss in

freeze-thaw resistance when steam cured at 70°C and 82°C.

(vii) The expansion in concrete mixes made of GU, HE and GUL cements reduced the

freeze-thaw resistance of concrete. The higher the concrete expansion, the lower

the durability factor. The reduction in freeze-thaw durability factor was due to three

factors. Firstly, the micrographic analysis showed that concrete mixes steam cured

at 82°C had microcracks prior to freeze-thaw testing. Secondly, concrete mixes

steam cured at 70°C exhibited greater 300-day expansions compared to concrete

mixes steam cured at 55°C. The greater expansion of the concrete steam cured at

70°C causes an increase in the internal stresses and thus there might be less room

to accommodate any additional stresses due to the freeze-thaw cycles before

cracking. Thirdly, concrete mixes steam cured at 70°C and 82°C had secondary

ettringite formation in air voids. This secondary ettringite formation may reduce

the available space that accommodates water expansion under freezing conditions.

153





acknowledge Holcim and Lafarge Canada for providing the cement, Omya Canada for

providing the limestone, Euclid Admixture Canada Inc. for providing the admixtures and

Dufferin Aggregates for providing the aggregates.

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[2] IBIS World (2015). Precast Concrete Manufacturing in Canada: Market Research

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[5] Min, T., Cho, I., Park, W., Choi, H., and Lee, H. (2014). Experimental Study on the

Development of Compressive Strength of Early Concrete Age using Calcium-Based

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[6] Tayyeb, A., Shazim, A.M., and Humayan, O. (2009). Production of Low Cost Self

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154

[9] Esping, O. (2008). Effect of Limestone Filler BET(H2O)-area on the Fresh and

Hardened Properties of Self-compacting Concrete. Cement and Concrete Research,

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Limestone in Cements at Levels of up to 15%. Portland Cement Association, PCA

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[11] Ramezanianpour, A.A., Khazali, M.H., and Vosoughi, P. (2013). Effect of Steam

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Affecting Delayed Ettringite Formation in Heat-cured Mortars. Cement and Concrete

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[14] Taylor, W., Famy, C., and Scrivener, K. (2001). Delayed Ettringite Formation.

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[15] Brunetaud, X., Linder, R., Divet, L., Duragrin, D., and Damidot, D. (2007). Effect of


Ettringite Formation. Materials and Structures, Vol. 40, No. 6, pp. 567-578.

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158

Chapter 6 - Key Findings, Contributions and Recommendations

6.1. Key Findings and Contributions

Key outcomes based on the research carried out in this thesis are:

1. A new method was developed to decouple the physical and the chemical effects of

limestone filler. This novel approach consisted of using a brucite filler with similar

physical properties to limestone filler and was used to measure the influence of each

effect of limestone filler on the mechanical and transport properties of steam cured

cement paste, mortar and concrete at 16 hours and 28 days.

2. The physical effect of limestone filler increases the compressive strength of mortar and

concrete at 16 hours. This increase was due to the acceleration in hydration rate and the

reduction in porosity of the mortar.

3. The chemical reactivity of limestone filler, leading to the production of calcium

monocarboaluminate, had an important role in enhancing the microstructure,

mechanical and transport properties of cement paste, mortar and concrete at 16 hours

and at 28 days.

4. At 16 hours, it is observed that the dilution effect alone adversely affects the mechanical

properties of concrete containing 15% limestone filler as a cement replacement.

However, this was offset by the combined beneficial influence of the: i) acceleration in

the hydration reactions, ii) modification of particle size distribution and, iii) production

of calcium monocarboaluminate. This resulted in a greater 16-hour compressive

strength of concrete containing 15% limestone filler compared to concrete made

without limestone filler.

5. Concrete containing 15% limestone filler had similar 28-day compressive strength

compared to concrete made without limestone filler because the dilution effect was

compensated for by the production of calcium monocarboaluminate.

6. The initial setting time was reduced with: increasing limestone filler content and

increasing LF fineness. This finding could be utilized to design shorter steam curing

regimes by applying steam curing sooner. This could create time and energy savings

without compromising the early age strength (i.e., at 12 and 16 hours).

159

7. Beyond the fineness of limestone filler, cement fineness was also an important factor

which influenced the chemical reactivity of limestone filler in pastes made without

silica fume, particularly at early ages (i.e., 16 hours). An increase in the cement fineness

increased the fraction of reacted limestone filler because the sulfate depletion point,

which marks the onset reaction of limestone filler, was reached sooner in finer cement

compared to relatively coarser cement. Therefore, to efficiently use limestone filler in

steam cured concrete, both limestone filler fineness and cement fineness should be

considered.

8. Limestone filler increased the 16-hour mechanical properties of concrete steam cured

at 55°C. However, this effect of limestone filler on the mechanical properties at 16

hours was not observed when the steam curing temperature increased from 55°C to

70°C and 82°C.

9. Limestone filler slightly reduced the expansion of concrete immersed in water at 23°C

for 300 days compared to concrete made without limestone filler. This reduction in the

concrete expansion was caused by the reduction in cement content, which reduced the

amount of DEF that could form in the system and thus reduced the expansion. In

addition, the reduced permeability in concrete mixes made with limestone filler might

also be a contributing factor in reducing the expansion.

10. GUL cement concrete containing 12% of interground limestone had similar hardened

properties and durability performance compared to concrete mixes made of GU cement

blended with 15% of 17µm and 3µm limestone filler used as cement replacement.

11. Although, at 300 days, the expansion of all concrete mixes were below 0.05%, the

corresponding freeze-thaw durability factors vary widely and were mainly controlled

by the steam curing temperature and the chemical composition of the cement. For

example, the durability factors for concrete (made with GU, HE, and GUL cements)

steam cured at 55, 70 and 82°C were 96-99%, 79-85%, and 56-73%, respectively. The

durability factors for concrete made with HS cement were above 92% for all steam

curing temperatures.

12. The mechanical and transport properties of concrete mixes made with HS cement and

steam cured at 70°C and 82°C were similar to concrete mixes made with GU, HE and

GUL cements at 300 days. However, the concrete expansion after 300 days of water

immersion and the loss in the freeze-thaw durability factor were significantly lower in

HS cement concrete compared to concrete mixes made of GU, HE and GUL cements.

160

This was due to the lower sulfate and alkali contents in HS cement compared to GU,

HE and GUL cements, which reduces the expansion due to DEF.

13. The expansion due to DEF in concrete mixes made of GU, HE and GUL cements

reduced the freeze-thaw resistance of concrete. The higher the concrete expansion, the

lower the durability factor. The reduction in the freeze-thaw durability factor was due

to three factors. Firstly, despite no visible surface cracking, the micrographic analysis

showed that concrete mixes steam cured at 82°C had microcracks prior to freeze-thaw

testing. Secondly, concrete mixes steam cured at 70°C exhibited greater 300-day

expansions compared to concrete mixes steam cured at 55°C. The greater expansion of

the concrete steam cured at 70°C yields an increase in the internal stresses and thus less

room to accommodate any additional stresses due to the freeze-thaw cycles before

cracking. Thirdly, concrete mixes steam cured at 70°C and 82°C had secondary

ettringite formation in air voids. This secondary ettringite formation may reduce the

available space that accommodates water expansion under freezing conditions resulting

in lower freeze-thaw resistance.

14. Self-consolidating concrete containing 5% silica fume and 15% limestone filler, steam

cured at 55°C, 70°C and 82°C, exhibited similar or superior mechanical and transport

properties and long term durability performance compared to comparable concrete

without limestone filler. The use of 15% limestone filler as cement replacement is a

viable option for the precast/prestressed applications.

6.2. Recommendations

(i) The effect of limestone particle size (i.e., 3µm compared to 17µm) on the

mechanical properties of steam cured concrete was significant at 12 and 16 hours.

It is recommended to investigate a wider range of limestone particle size which are

available in the Canadian market (for example, 0.7µm, 1µm, 30µm and 10µm).

(ii) Replacing 15% of the cement by 17µm and 3µm limestone filler had no negative

impact on the hardened properties and durability performance at 28 and 300 days.

It is recommended to investigate the effect of higher limestone filler content (for

example, 20% to 30%), which will assist in identifying the limestone filler content

at which limestone filler starts to cause a significant impact on the hardened

properties and durability performance of steam cured concrete.

161

(iii) Based on the results of this thesis, for steam cured concrete containing 5% silica

fume, limiting the steam curing temperature to 70°C was critical to limit the damage

caused by concrete expansion due to DEF. In the case where the steam curing

temperature can rise to a temperature greater than 70°C, it is recommended to use

a cement with low sulfate and alkali contents such as HS cement.

162

Appendix A - Testing Data

This appendix presents the material properties and the raw data for the compressive

strength, UPV, RCPT and concrete expansion measurements. Additional SEM images are

also presented in this appendix.

A.1. Particle Size Distribution of Sand and Aggregate

In this section, the particle size distribution of sand and coarse aggregate is presented and

compared to the upper and lower limits set by ASTM C33, as presented in Figures A.1 and

A.2.

Figure A.1: Particle Size Distribution of Sand

0

10

20

30

40

50

60

70

80

90

100

0.01 0.1 1 10 100

Per

centa

ge

Pas

sing (

%)

Sieve Size (mm)

ASTM C33-Limits Sand Grading

163

Figure A.2: Particle Size Distribution of Coarse Aggregate

A.2. Materials Properties

This section presents the fineness modulus of sand, specific gravity and absorption of sand

and coarse aggregate, as presented in Table A.1. In addition, the density of the raw

materials used in this thesis is presented in Table A.2.

Table A.1: Properties of Sand and Coarse Aggregate

Properties Sand Coarse Aggregate

Fineness Modulus 2.84 ---


Absorption (%) 0.61 1.75

0

10

20

30

40

50

60

70

80

90

100

1 10 100

Per

centa

ge

Pas

sing (

%)

Sieve Size (mm)

ASTM C33-Limits Coarse Aggregate Grading

164

Table A.2: Density of Raw Materials

Material Density (kg/m3)

Cement 3120

LF 2700

SF 2250

BR 2445

Coarse Aggregate 2700

Sand 2720

HRWR 1190

AEA 1007

A.3. Mixing and Batching of Concrete

Due to the low water-to-cement ratio in concrete, the available 60-litre pan mixer did not

produce a uniform concrete mix when used. Therefore, the concrete was produced in two

30-litre batches using a drum mixer. To evaluate the repeatability of batching, initial trials

was conducted and the fresh properties and compressive strength were evaluated for each

batch. The fresh properties were evaluated using fresh air content, fresh density and slump

flow tests. Tables A.3 and A.4 present a comparison of fresh properties and compressive

strength between trail batches for mixes GU, GU-17µm and GU-3µm. In addition, the fresh

air content was compared in the concrete mix designs which were repeated in Chapters 4

and 5, as presented in Table A.5. The results of Tables A.3, A.4 and A.5 shows a good

repeatability of the concrete batching process.

Table A.3: Comparison of Fresh Properties of Concrete Batches

Mix ID

Fresh Air Content (%) Slump Flow (mm) Density (kg/m3)

Batch

1

Batch

2

Difference

(%)

Batch

1

Batch

2

Difference

(%)

Batch

1

Batch

2

Difference

(%)

GU 5.0 4.9 2.0 670 690 2.9 2385 2405 0.8

GU-17µm 5.6 5.2 7.4 635 665 4.6 2447 2415 1.3

GU-3µm 5.1 5.0 2.0 660 660 0.0 2428 2450 0.9

165

Table A.4: Comparison of Compressive Strength (average of three tests) of Concrete

Batches

Mix ID

16-Hour Compressive Strength (MPa) 28-Day Compressive Strength (MPa)

Batch 1 Batch 2 Difference

(%) Batch 1 Batch 2

Difference

(%)

GU 47.2 48.4 2.5 70.9 74.1 4.4

GU-17µm 49.7 50.3 1.2 68.1 70.3 3.2

GU-3µm 54.8 56 2.2 72.4 74.2 2.5

Table A.5: Comparison of Fresh Air Content in Concrete Mixes Repeated in Chapters 4

and 5

Mix ID Fresh Air Content (%)

Chapter 4 Chapter 5 Difference (%)

GU 5.0 5.2 3.9

GU-17µm 5.4 5.3 1.9

GU-3µm 5.1 5.0 2.0

HE 5.0 5.4 7.7

HE-17µm 5.2 4.9 5.9

HE-3µm 5.4 5.2 3.8

166

A.4. Mortar and Concrete Mix Designs

This section presents the mortar and concrete mix designs used in this thesis. Tables A.6

and A.7 present the mortar and concrete mix designs used in Chapter 2, respectively. Table

A.8 presents the mortar mix designs used in Chapter 3. Table A.9 presents the concrete

mix designs used in Chapter 4 and 5.

Table A.6: Mortar Mix Designs (5 kg Batch)

Mix ID

Weight (g)

Cement LF BF Fine Agg. Water

C 1497.0 0.0 0.0 2994.0 509.0

LF 1272.5 224.6 0.0 2994.0 432.6

BF 1272.5 0.0 224.6 2994.0 432.6

Table A.7: Concrete Mix Designs (30-Litre Batch)

Mix ID Cement LF BF

Coarse

Agg.

Fine

Agg. Water HRWR

kg ml

C 13.5 0.0 0.0 27.0 27.6 4.6 40.5

LF 11.5 2.0 0.0 27.0 28.7 3.9 162.0

BF 11.5 0.0 2.0 27.0 28.4 3.9 162.0

A.3.2. Mortar Mix Designs used in Chapter 3

167

Table A.8: Mortar Mix Designs (5 kg Batch)

Mix ID

Mixing Weight (g)

Cement LF Fine Aggregate Water

GU 1483.7 0.0 2967.4 549.0

GU-5-17µm 1409.5 74.2 2967.4 521.5

GU-10-17µm 1335.3 148.4 2967.4 494.1

GU-15-17µm 1261.1 222.6 2967.4 466.6

GU -5-12µm 1409.5 74.2 2967.4 521.5

GU-10-12µm 1335.3 148.4 2967.4 494.1

GU-15-12µm 1261.1 222.6 2967.4 466.6

GU-5-3µm 1409.5 74.2 2967.4 521.5

GU-10-3µm 1335.3 148.4 2967.4 494.1

GU-15-3µm 1261.1 222.6 2967.4 466.6

HE 1483.7 0.0 2967.4 549.0

HE-5-17µm 1409.5 74.2 2967.4 521.5

HE-10-17µm 1335.3 148.4 2967.4 494.1

HE-15-17µm 1261.1 222.6 2967.4 466.6

HE-5-12µm 1409.5 74.2 2967.4 521.5

HE-10-12µm 1335.3 148.4 2967.4 494.1

HE-15-12µm 1261.1 222.6 2967.4 466.6

HE-5-3µm 1409.5 74.2 2967.4 521.5

HE-10-3µm 1335.3 148.4 2967.4 494.1

HE-15-3µm 1261.1 222.6 2967.4 466.6

168

Table A.9: Concrete Mix Designs (30-Litre Batch)

Mix ID Cement SF

Coarse

Agg.

Fine

Agg. Water

LF

AEA HRWR Size

(μm) kg

kg ml

GU 12.8 0.7 28.5 25.3 4.5 --- 0.0 5.0 121.5

GU-17µm 10.8 0.7 28.5 25.3 3.7 17 2.0 16.2 310.5

GU-3µm 10.8 0.7 28.5 25.3 3.7 3 2.0 20.0 330.8

HE 12.8 0.7 28.5 25.3 4.5 --- 0.0 6.1 135.0

HE-17µm 10.8 0.7 28.5 25.3 3.7 17 2.0 26.3 317.3

HE-3µm 10.8 0.7 28.5 25.3 3.7 3 2.0 32.4 337.5

GUL 12.8 0.7 28.5 25.3 3.8 --- 0.0 25.7 324.0

HS 12.8 0.7 28.5 25.3 4.5 --- 0.0 3.4 67.5

HS-17µm 10.8 0.7 28.5 25.3 3.6 17 2.0 8.1 256.5

HS-3µm 10.8 0.7 28.5 25.3 3.6 3 2.0 9.5 270.0

169

A.5. Chapter 2 Results

Table A.10: Raw Data of Laboratory Testing Carried out in Chapter 2

Mix Sample

#

Total

Porosity

(%)

Cube

Compressive

Strength of

Mortar

(MPa)

Concrete

Compressive

Strength

(MPa)

RCPT - Paste

(Coulombs)

RCPT -

Mortar

(Coulombs)

RCPT -

Concrete

(Coulombs)

Initial

Sorptivity -

Paste

(×10-4

mm/sec0.5)

Initial

Sorptivity

- Mortar

(×10-4

mm/sec0.5)

Initial

Sorptivity -

Concrete

(×10-4

mm/sec0.5)

16 H 28 D 16 H 28 D 16 H 28 D 16 H 28 D 16 H 28 D 16 H 28 D 16 H 28 D 16 H 28 D 16 H 28 D

C

1 9.4 5.9 66.4 91.0 59.1 83.2 11780 9234 4657 3123 2845 1193 25.1 14.9 16.0 14.2 11.1 10.1

2 9.0 5.9 67.9 93.0 61.7 85.4 11256 8765 4978 2978 2687 1217 24.7 15.8 16.7 15.0 11.9 10.3

3 9.6 6.3 67.5 92.0 59.2 86.4 10978 8551 5206 2914 2988 1268 26.9 15.3 15.9 15.2 12.4 9.9

Avg. 9.3 6.0 67.3 92.0 60.0 85.0 11338 8850 4947 3005 2840 1226 25.6 15.3 16.2 14.8 11.8 10.1

SD 0.3 0.2 0.8 1.0 1.5 1.6 407 349 276 107 151 38 1.2 0.5 0.4 0.5 0.7 0.2

COV (%) 3.3 3.8 1.2 1.1 2.5 1.9 3.6 3.9 5.6 3.6 5.3 3.1 4.5 2.9 2.7 3.6 5.6 2.0

LF

1 8.1 6.1 74.0 96.0 64.1 83.7 10903 7543 4317 2545 2380 949 24.5 13.5 15.5 12.9 11.4 8.9

2 7.8 6.4 72.5 94.0 66.8 82.6 10045 7856 4678 2272 2567 838 23.9 14.1 15.1 12.5 11.1 8.5

3 7.8 6.1 70.9 93.2 64.1 85.7 9499 7950 4745 2353 2553 859 25.1 14.4 15.0 13.6 11.1 8.7

Avg. 7.9 6.2 72.5 94.4 65.0 84.0 10149 7783 4580 2390 2500 882 24.5 14.0 15.2 13.0 11.2 8.7

SD 0.2 0.2 1.6 1.4 1.6 1.6 708 213 230 140 104 59 0.6 0.5 0.3 0.6 0.2 0.2

COV (%) 2.2 2.8 2.1 1.5 2.4 1.9 7.0 2.7 5.0 5.9 4.2 6.7 2.4 3.3 1.7 4.3 1.5 2.3

BF

1 8.5 5.9 70.0 88.6 61.1 83.3 10956 8122 4657 2434 2898 997 25.5 14.8 16.0 14.1 12.1 9.1

2 8.9 5.6 71.0 91.9 63.1 81.9 10045 8512 4798 2657 2676 1123 25.1 15.3 16.2 14.4 11.4 9.7

3 8.7 6.0 67.5 89.5 64.8 79.3 10898 8530 4945 2904 2706 1033 24.7 14.9 15.8 13.5 11.9 9.7

Avg. 8.7 5.8 69.5 90.0 63.0 81.5 10633 8388 4800 2665 2760 1051 25.1 15.0 16.0 14.0 11.8 9.5

SD 0.2 0.2 1.8 1.7 1.9 2.0 510 231 144 235 120 65 0.4 0.3 0.2 0.5 0.4 0.3

COV (%) 2.3 3.6 2.6 1.9 2.9 2.5 4.8 2.7 3.0 8.8 4.4 6.2 1.6 1.8 1.3 3.3 3.1 3.6

16 H: 16 hours, 28 D: 28 days

170

A.6 Chapter 3 Results

Table A.11: Hydration Peak of Cement Pastes

Mix Hydration Peak (mW/g) Avg.

(mW/g) SD

(mW/g)

COV

(%) 1 2 3

GU 3.82 3.87 3.82 3.84 0.03 0.8

G-5-17 4.02 3.99 3.96 3.99 0.03 0.8

G-10-17 4.00 4.03 4.03 4.02 0.02 0.4

G-15-17 4.09 4.10 4.07 4.09 0.02 0.4

G-5-12 3.91 3.94 3.97 3.94 0.03 0.8

G-10-12 4.00 4.02 4.04 4.02 0.02 0.5

G-15-12 4.10 4.11 4.05 4.09 0.03 0.8

G-5-3 4.02 3.90 3.97 3.96 0.06 1.5

G-10-3 4.15 4.19 4.12 4.15 0.04 0.8

G-15-3 4.34 4.36 4.35 4.35 0.01 0.2

HE 5.27 5.15 4.99 5.14 0.14 2.7

H-5-17 5.20 5.30 5.40 5.30 0.10 1.9

H-10-17 5.41 5.49 5.48 5.46 0.04 0.8

H-15-17 5.81 5.77 5.82 5.80 0.03 0.5

H-5-12 5.44 5.46 5.48 5.46 0.02 0.4

H-10-12 5.69 5.74 5.86 5.76 0.09 1.5

H-15-12 5.99 6.01 6.02 6.01 0.02 0.3

H-5-3 5.74 5.83 5.85 5.81 0.06 1.0

H-10-3 5.72 5.58 5.71 5.67 0.08 1.4

H-15-3 6.09 6.04 6.07 6.07 0.03 0.4

171

Table A.12: Total Heat Released of Cement Pastes after 20 Hours of Hydration

Mix

Total Heat Released after 20 Hours of

Hydration (J/g)

Avg.

(mW/g) SD

(mW/g)

COV

(%) 1 2 3

GU 161.3 159.5 161.0 160.6 1.0 0.6

G-5-17 168.4 170.4 167.7 168.8 1.4 0.8

G-10-17 172.3 170.4 170.7 171.1 1.0 0.6

G-15-17 173.1 173.7 174.9 173.9 0.9 0.5

G-5-12 168.4 169.3 164.2 167.3 2.7 1.6

G-10-12 171.4 172.3 170.1 171.3 1.1 0.6

G-15-12 173.4 173.9 175.8 174.4 1.2 0.7

G-5-3 170.2 173.2 172.9 172.1 1.7 1.0

G-10-3 174.9 177.4 178.6 177.0 1.9 1.1

G-15-3 186.9 187.7 185.1 186.6 1.3 0.7

HE 184.7 183.5 179.6 182.6 2.7 1.5

H-5-17 190.3 189.4 188.1 189.3 1.1 0.6

H-10-17 195.4 195.2 192.1 194.2 1.8 0.9

H-15-17 200.5 201.5 200.9 201.0 0.5 0.3

H-5-12 194.5 193.2 190.5 192.7 2.0 1.1

H-10-12 199.5 197.4 198.8 198.6 1.1 0.5

H-15-12 202.5 201.5 201.7 201.9 0.5 0.3

H-5-3 197.9 197.1 195.1 196.7 1.4 0.7

H-10-3 199.2 198.2 194.1 197.2 2.7 1.4

H-15-3 204.5 204.1 201.4 203.3 1.7 0.8

172

Table A.13: Ca(OH)2 Content in Cement Pastes at 16 Hours and 28 Days

Mix

Ca(OH)2 Content (wt%)

16 Hours 28 Days

1 2 3 Avg. SD COV(%) 1 2 3 Avg. SD COV(%)

GU 11.8 12.1 11.8 11.9 0.2 1.5 13.9 13.8 13.8 13.8 0.1 0.5

G-5-17 12.5 12.2 12.4 12.4 0.2 1.3 14.3 14.0 14.0 14.1 0.2 1.2

G-10-17 13.0 12.6 12.5 12.7 0.3 2.2 13.7 13.9 14.2 13.9 0.2 1.7

G-15-17 12.8 12.5 12.7 12.7 0.2 1.2 13.1 13.5 13.5 13.4 0.2 1.7

G-5-12 12.1 12.4 12.1 12.2 0.2 1.4 14.2 14.0 13.9 14.0 0.2 1.2

G-10-12 12.6 12.5 12.3 12.5 0.2 1.3 13.9 13.8 13.7 13.8 0.1 0.9

G-15-12 12.4 12.7 12.3 12.5 0.2 1.7 13.7 13.8 13.6 13.7 0.1 0.9

G-5-3 12.8 12.3 12.4 12.5 0.3 2.1 14.1 14.0 14.2 14.1 0.1 0.8

G-10-3 12.6 12.6 13.1 12.8 0.3 2.4 14.2 14.2 13.8 14.1 0.3 1.8

G-15-3 12.5 12.6 12.7 12.6 0.1 0.9 13.9 13.8 13.6 13.8 0.1 0.9

HE 12.1 12.1 12.5 12.2 0.2 2.0 14.0 14.0 14.2 14.1 0.1 0.7

H-5-17 12.7 12.5 12.2 12.5 0.3 2.0 14.0 14.4 14.3 14.2 0.2 1.4

H-10-17 12.9 12.5 12.8 12.7 0.2 1.6 14.8 14.6 14.3 14.6 0.2 1.6

H-15-17 12.7 12.9 12.5 12.7 0.2 1.7 14.6 14.4 14.8 14.6 0.2 1.5

H-5-12 12.8 12.5 13.0 12.8 0.3 2.0 14.4 14.4 14.5 14.4 0.1 0.4

H-10-12 12.9 12.5 12.5 12.6 0.2 1.8 14.7 14.6 14.9 14.7 0.1 0.9

H-15-12 12.5 12.6 13.0 12.7 0.2 2.0 14.6 14.7 15.0 14.8 0.2 1.2

H-5-3 12.7 12.9 13.0 12.9 0.1 1.1 14.6 14.6 15.0 14.7 0.2 1.7

H-10-3 12.7 12.7 12.8 12.7 0.0 0.3 14.7 14.7 14.8 14.7 0.0 0.2

H-15-3 12.5 12.4 12.7 12.5 0.2 1.4 14.4 14.5 14.6 14.5 0.1 0.9

173

Table A.14: LF Reactivity in Cement Pastes at 16 Hours and 28 Days

Mix

LF Reactivity (wt%)

16 Hours 28 Days

1 2 3 Avg. SD 1 2 3 Avg. SD

GU 0.00 0.00 0.00 0.00 0.00 0.15 0.14 0.13 0.14 0.01

G-5-17 0.02 0.01 0.00 0.01 0.01 0.42 0.40 0.38 0.40 0.02

G-10-17 0.07 0.05 0.09 0.07 0.02 1.30 1.22 1.05 1.19 0.12

G-15-17 0.10 0.09 0.08 0.09 0.01 1.57 1.60 1.51 1.56 0.05

G-5-12 0.02 0.01 0.00 0.01 0.01 0.25 0.25 0.28 0.26 0.02

G-10-12 0.11 0.10 0.09 0.10 0.01 1.40 1.20 1.24 1.28 0.10

G-15-12 0.16 0.14 0.12 0.14 0.02 1.29 1.15 1.10 1.18 0.09

G-5-3 0.03 0.02 0.04 0.03 0.01 0.33 0.30 0.30 0.31 0.02

G-10-3 0.18 0.17 0.16 0.17 0.01 1.96 1.96 1.90 1.94 0.03

G-15-3 0.49 0.46 0.49 0.48 0.02 2.30 2.26 2.25 2.27 0.03

HE 0.06 0.05 0.04 0.05 0.01 1.05 0.93 0.90 0.96 0.08

H-5-17 0.10 0.11 0.06 0.09 0.03 1.47 1.47 1.41 1.45 0.03

H-10-17 0.33 0.32 0.28 0.31 0.03 1.12 1.14 1.10 1.12 0.02

H-15-17 0.14 0.11 0.11 0.12 0.02 1.22 1.12 1.02 1.12 0.10

H-5-12 0.37 0.34 0.31 0.34 0.03 1.54 1.55 1.47 1.52 0.04

H-10-12 0.76 0.74 0.72 0.74 0.02 1.38 1.36 1.40 1.38 0.02

H-15-12 0.62 0.59 0.59 0.60 0.02 1.79 1.65 1.48 1.64 0.15

H-5-3 0.67 0.66 0.62 0.65 0.03 1.44 1.44 1.41 1.43 0.02

H-10-3 0.97 0.93 0.92 0.94 0.03 1.62 1.62 1.56 1.60 0.03

H-15-3 1.37 1.35 1.33 1.35 0.02 2.21 2.05 1.83 2.03 0.19

174

Table A.15: The Degree of Hydration of Cement Pastes at 16 Hours and 28 Days

Mix

Degree of Hydration

16 Hours 28 Days


GU 0.61 0.62 0.62 0.62 0.01 0.9 0.81 0.82 0.82 0.82 0.01 0.6

G-5-17 0.66 0.66 0.64 0.65 0.01 2.1 0.85 0.84 0.84 0.84 0.01 0.7

G-10-17 0.68 0.66 0.65 0.66 0.02 2.6 0.85 0.86 0.84 0.85 0.01 1.2

G-15-17 0.66 0.66 0.66 0.66 0.00 0.1 0.83 0.84 0.85 0.84 0.01 1.2

G-5-12 0.67 0.65 0.65 0.66 0.01 1.6 0.85 0.84 0.85 0.85 0.01 0.6

G-10-12 0.67 0.67 0.65 0.66 0.01 1.7 0.84 0.83 0.88 0.85 0.03 3.0

G-15-12 0.66 0.66 0.64 0.65 0.01 1.9 0.84 0.84 0.83 0.84 0.01 0.9

G-5-3 0.66 0.65 0.63 0.65 0.01 2.3 0.85 0.86 0.83 0.85 0.02 2.1

G-10-3 0.66 0.65 0.67 0.66 0.01 1.2 0.85 0.85 0.86 0.85 0.00 0.6

G-15-3 0.68 0.66 0.66 0.67 0.01 1.8 0.84 0.84 0.86 0.85 0.01 1.4

HE 0.64 0.64 0.62 0.63 0.01 2.0 0.82 0.81 0.84 0.82 0.02 2.1

H-5-17 0.66 0.67 0.66 0.66 0.01 1.2 0.83 0.82 0.83 0.83 0.01 0.9

H-10-17 0.67 0.67 0.64 0.66 0.02 2.4 0.82 0.82 0.86 0.83 0.02 2.5

H-15-17 0.65 0.67 0.65 0.66 0.01 1.7 0.82 0.83 0.84 0.83 0.01 1.5

H-5-12 0.67 0.68 0.66 0.67 0.01 1.7 0.84 0.85 0.83 0.84 0.01 1.5

H-10-12 0.68 0.67 0.65 0.67 0.01 2.2 0.84 0.84 0.85 0.84 0.01 0.9

H-15-12 0.68 0.68 0.64 0.67 0.02 3.7 0.84 0.84 0.84 0.84 0.00 0.3

H-5-3 0.67 0.67 0.66 0.67 0.01 1.0 0.86 0.86 0.85 0.86 0.00 0.4

H-10-3 0.67 0.67 0.66 0.67 0.01 1.0 0.87 0.87 0.85 0.86 0.01 1.4

H-15-3 0.66 0.67 0.69 0.67 0.02 2.4 0.85 0.84 0.86 0.85 0.01 1.2

175

Table A.16: Compressive Strength of Mortar Cubes at 12 and 16 Hours

Mix

Degree of Hydration

12 Hours 16 Hours


GU 34.0 34.4 34.8 34.4 0.4 1.2 38.2 37.6 38.8 38.2 0.6 1.6

G-5-17 36.8 36.0 37.0 36.6 0.5 1.4 41.6 40.8 42.0 41.5 0.6 1.5

G-10-17 35.2 36.0 35.6 35.6 0.4 1.1 38.0 37.2 39.2 38.1 1.0 2.6

G-15-17 36.1 35.6 35.2 35.6 0.5 1.3 36.4 38.8 36.8 37.3 1.3 3.4

G-5-12 34.4 35.2 33.6 34.4 0.8 2.3 39.2 39.6 38.8 39.2 0.4 1.0

G-10-12 34.4 34.0 34.8 34.4 0.4 1.2 41.2 41.6 42.4 41.7 0.6 1.5

G-15-12 34.4 35.2 33.6 34.4 0.8 2.3 37.0 37.0 37.0 37.0 0.0 0.0

G-5-3 34.8 34.4 35.2 34.8 0.4 1.1 38.4 37.6 37.0 37.7 0.7 1.9

G-10-3 35.2 36.0 35.2 35.5 0.5 1.3 38.4 38.8 39.6 38.9 0.6 1.6

G-15-3 35.6 36.0 36.4 36.0 0.4 1.1 36.8 37.6 38.4 37.6 0.8 2.1

HE 40.4 40.4 40.4 40.4 0.0 0.0 46.0 45.0 46.0 45.7 0.6 1.3

H-5-17 42.8 42.8 41.6 42.4 0.7 1.6 46.4 47.6 47.2 47.1 0.6 1.3

H-10-17 42.8 43.6 44.0 43.5 0.6 1.4 48.0 48.0 47.8 47.9 0.1 0.2

H-15-17 45.8 44.8 43.8 44.8 1.0 2.2 46.0 47.6 45.6 46.4 1.1 2.3

H-5-12 44.4 42.2 43.0 43.2 1.1 2.6 48.2 47.6 48.0 47.9 0.3 0.6

H-10-12 43.5 44.4 43.3 43.7 0.6 1.3 48.1 47.8 49.2 48.4 0.7 1.5

H-15-12 44.8 44.4 44.0 44.4 0.4 0.9 48.0 48.0 48.8 48.3 0.5 1.0

H-5-3 42.4 42.8 42.4 42.5 0.2 0.5 46.4 48.8 48.0 47.7 1.2 2.6

H-10-3 42.0 45.6 44.0 43.9 1.8 4.1 48.0 47.2 48.4 47.9 0.6 1.3

H-15-3 46.4 46.8 45.2 46.1 0.8 1.8 51.2 50.8 50.4 50.8 0.4 0.8

176

Table A.17: Compressive Strength of Mortar Cubes at 3, 7 and 28 Days

Mix

Mortar Cube Compressive Strength (MPa)

3 Days 7 Days 28 Days

1 2 3 Avg. SD COV

(%) 1 2 3 Avg. SD

COV

(%) 1 2 3 Avg. SD

COV

(%)

GU 43.5 44.0 43.0 43.5 0.5 1.1 47.5 46.0 46.0 46.5 0.9 1.9 60.0 60.2 60.6 60.3 0.3 0.5

G-5-17 46.0 45.0 44.0 45.0 1.0 2.2 50.0 50.0 49.0 49.7 0.6 1.2 63.6 63.2 64.2 63.7 0.5 0.8

G-10-17 42.8 43.0 43.5 43.1 0.4 0.8 48.0 47.0 46.0 47.0 1.0 2.1 63.2 63.0 63.8 63.3 0.4 0.7

G-15-17 41.6 42.0 42.4 42.0 0.4 1.0 45.2 46.6 46.6 46.1 0.8 1.8 59.0 55.5 59.0 57.8 2.0 3.5

G-5-12 45.2 44.4 44.8 44.8 0.4 0.9 48.0 47.2 48.0 47.7 0.5 1.0 60.4 60.0 61.0 60.5 0.5 0.8

G-10-12 46.4 47.2 46.0 46.5 0.6 1.3 49.2 49.6 49.6 49.5 0.2 0.5 59.0 61.2 60.0 60.1 1.1 1.8

G-15-12 42.8 43.2 42.4 42.8 0.4 0.9 46.4 45.2 45.6 45.7 0.6 1.3 56.8 58.0 58.0 57.6 0.7 1.2

G-5-3 44.0 43.6 42.8 43.5 0.6 1.4 48.8 49.2 48.0 48.7 0.6 1.3 59.2 60.0 59.2 59.5 0.5 0.8

G-10-3 44.4 44.0 45.6 44.7 0.8 1.9 49.6 50.4 50.0 50.0 0.4 0.8 58.0 59.0 59.0 58.7 0.6 1.0

G-15-3 43.6 45.2 45.2 44.7 0.9 2.1 47.4 46.4 49.0 47.6 1.3 2.8 56.8 58.0 61.6 58.8 2.5 4.2

HE 53.1 49.2 52.2 51.5 2.0 4.0 53.6 52.0 51.6 52.4 1.1 2.0 61.2 64.8 63.0 63.0 1.8 2.9

H-5-17 52.2 51.2 52.4 51.9 0.6 1.2 54.4 52.0 52.8 53.1 1.2 2.3 60.8 67.2 67.6 65.2 3.8 5.9

H-10-17 52.8 53.6 52.4 52.9 0.6 1.2 54.0 55.4 54.0 54.5 0.8 1.5 65.2 61.6 65.6 64.1 2.2 3.4

H-15-17 49.6 49.8 50.2 49.9 0.3 0.6 53.0 52.0 52.5 52.5 0.5 1.0 66.0 66.4 65.0 65.8 0.7 1.1

H-5-12 51.2 50.8 50.0 50.7 0.6 1.2 53.9 52.0 53.6 53.2 1.0 1.9 63.3 63.8 63.9 63.7 0.3 0.5

H-10-12 50.8 50.8 54.0 51.9 1.8 3.6 53.0 53.9 54.2 53.7 0.6 1.2 66.0 67.0 66.0 66.3 0.6 0.9

H-15-12 55.0 52.8 54.0 53.9 1.1 2.0 52.8 55.6 58.0 55.5 2.6 4.7 68.0 67.0 68.0 67.7 0.6 0.9

H-5-3 51.2 51.0 51.6 51.3 0.3 0.6 51.6 56.4 57.6 55.2 3.2 5.8 62.4 64.4 66.0 64.3 1.8 2.8

H-10-3 52.0 52.0 52.8 52.3 0.5 0.9 57.6 58.8 56.8 57.7 1.0 1.7 67.6 66.4 67.6 67.2 0.7 1.0

H-15-3 56.0 54.6 54.8 55.1 0.8 1.4 58.0 58.4 59.6 58.7 0.8 1.4 70.4 70.4 67.6 69.5 1.6 2.3

177

Figure A.3: Relationship Between LF Reactivity, Ca(OH)2 Content and Degree of

Hydration at 16 Hours

0.5

0.55

0.6

0.65

0.7

11.8

12.2

12.6

13.0

13.4

13.8

14.2

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

Deg

ree

of

Hyd

rati

on

Ca(

OH

) 2 C

on

ten

t (w

t%)

LF Reactivity (wt%)

0% LF 5% LF 10% LF 15% LF

Ca(OH)2 Content

Degree of Hydration

178

A.7 Chapter 4 and 5 Results

A.7.1 Cement Paste and Mortar Results

Table A.18: Thermal Analysis Results of Cement Pastes Steam Cured at 55°C

Mix ID Sample #

Ca(OH)2 Content

(wt%) LF Reactivity (wt%)

Degree of

Hydration

16 Hrs. 28 Days 16 Hrs. 28 Days 16 Hrs. 28 Days

GU

1 7.80 8.36 0.02 0.28 0.57 0.70

2 7.81 8.42 0.01 0.31 0.55 0.68

3 7.77 8.34 0.00 0.29 0.54 0.69

Avg. 7.79 8.37 0.01 0.29 0.55 0.69

SD 0.02 0.04 0.01 0.01 0.02 0.01

COV(%) 0.3 0.5 --- 4.8 2.9 1.4

GU-17µm

1 7.53 8.33 0.44 1.06 0.52 0.66

2 7.51 8.17 0.47 1.14 0.53 0.64

3 7.64 8.31 0.44 1.13 0.54 0.68

Avg. 7.56 8.27 0.45 1.11 0.53 0.66

SD 0.07 0.09 0.02 0.04 0.01 0.02

COV(%) 0.9 1.0 3.7 3.8 1.7 3.0

GU-3µm

1 7.29 7.91 0.88 1.60 0.52 0.66

2 7.27 7.77 0.91 1.51 0.55 0.67

3 7.3 7.99 0.86 1.52 0.54 0.68

Avg. 7.29 7.89 0.88 1.54 0.54 0.67

SD 0.02 0.11 0.03 0.05 0.02 0.01

COV(%) 0.2 1.4 2.9 3.2 3.3 1.7

HE

1 7.74 8.28 0.30 0.49 0.59 0.74

2 7.69 8.1 0.27 0.49 0.6 0.73

3 7.6 8.29 0.26 0.46 0.61 0.73

Avg. 7.68 8.22 0.28 0.48 0.60 0.73

SD 0.07 0.11 0.02 0.02 0.01 0.00

COV(%) 0.9 1.3 6.8 3.6 2.1 0.5

HE-17µm

1 7.40 8.13 0.49 1.16 0.56 0.70

2 7.39 8.1 0.49 1.25 0.56 0.71

3 7.37 8.21 0.47 1.22 0.57 0.7

Avg. 7.39 8.15 0.48 1.21 0.56 0.70

SD 0.02 0.06 0.01 0.05 0.01 0.01

COV(%) 0.2 0.7 2.7 3.8 1.2 0.9

HE-3µm

1 7.00 7.86 0.94 1.81 0.58 0.71

2 6.97 7.78 0.92 1.7 0.56 0.7

3 7.03 7.8 0.89 1.89 0.56 0.72

Avg. 7.00 7.81 0.92 1.80 0.57 0.71

SD 0.03 0.04 0.03 0.10 0.01 0.01

COV(%) 0.4 0.5 2.7 5.3 2.5 1.4

179

Table A.19: Cube Compressive Strength of Mortars Steam Cured at 55°C

Mix ID Sample # Compressive Strength of Mortars (MPa)


GU

1 55.8 58.4 65.3 68.9 82.0

2 51.0 56.3 67.2 69.9 78.9

3 54.0 58.1 64.3 70.0 77.9

Avg. 53.6 57.6 65.6 69.6 79.6

SD 2.4 1.1 1.5 0.6 2.1

COV(%) 4.5 2.0 2.2 0.9 2.7

GU-17µm

1 61.2 64.5 70.5 72.1 82.4

2 62.3 67.4 73.2 74.5 80.6

3 60.9 64.9 71.1 73.0 83.4

Avg. 61.5 65.6 71.6 73.2 82.1

SD 0.7 1.6 1.4 1.2 1.4

COV(%) 1.2 2.4 2.0 1.7 1.7

GU-3µm

1 64.8 68.6 71.7 73.3 86.7

2 61.3 69.3 74.6 78.0 84.1

3 63.1 70.3 74.5 76.7 81.2

Avg. 63.1 69.4 73.6 76.0 84.0

SD 1.8 0.9 1.6 2.4 2.8

COV(%) 2.8 1.2 2.2 3.2 3.3

HE

1 61.1 62.5 68.3 72.0 79.4

2 55.3 66.6 68.0 70.1 78.3

3 56.8 64.1 68.9 73.9 83.1

Avg. 57.7 64.4 68.4 72.0 80.3

SD 3.0 2.1 0.5 1.9 2.5

COV(%) 5.2 3.2 0.7 2.6 3.1

HE-17µm

1 59.8 67.0 73.9 74.9 82.8

2 59.3 65.2 70.1 71.2 80.2

3 60.9 68.2 70.4 75.3 81.2

Avg. 60.0 66.8 71.5 73.8 81.4

SD 0.8 1.5 2.1 2.3 1.3

COV(%) 1.4 2.3 2.9 3.1 1.6

HE-3µm

1 60.2 67.1 73.4 78.3 83.1

2 64.2 70.5 77.6 78.5 82.3

3 62.0 70.0 77.0 76.8 83.4

Avg. 62.1 69.2 76.0 77.9 82.9

SD 2.0 1.8 2.3 0.9 0.6

COV(%) 3.2 2.7 3.0 1.2 0.7

180

A.7.2 Fresh Properties of Concrete

Table A.20: Fresh Properties of Concrete (Yield = 1 m3 ± 0.012 m3)

Mix ID

Plastic Air

Content

(%)

Plastic

Density

(kg/m3)

Slump L-box

(H2/H1)

Column

Segregation

(%) Flow

(mm)

T50

(sec) VSI

J-Ring

(mm)

GU 5.1* 2395 680 4 0.5 660 0.67 2.5

GU-17µm 5.4* 2431 650 4 0 635 0.58 1.5

GU-3µm 5.1* 2439 660 5 0 640 0.50 1.0

HE 5.2* 2444 650 5 0.5 638 0.64 1.6

HE-17µm 5.1* 2439 680 4 0 660 0.56 1.5

HE-3µm 5.3* 2443 650 5 0 630 0.53 0.8

GUL 5.7 --- 695 --- 0.5 --- --- ---

HS 4.9 --- 630 --- 0.5 --- --- ---

HS-17µm 5.3 --- 685 --- 0 --- --- ---

HS-3µm 5.0 --- 645 --- 0 --- --- ---

* Average of two values measured in Chapter 4 and 5.

181

A.7.3 Mechanical Properties of Concrete

Table A.21: Elastic Modulus Values of Concrete Steam Cured at 55°C

Mix ID Sample # Elastic Modulus (GPa)


GU

1 26.0 32.9 35.0 38.0 40.9

2 25.9 32.0 35.4 37.0 40.3

3 26.3 32.5 34.7 37.0 41.0

Avg. 26.1 32.5 35.0 37.3 40.7

SD 0.2 0.5 0.4 0.6 0.4

COV(%) 0.8 1.4 1.0 1.6 0.9

GU-17µm

1 27.9 33.5 36.0 38.0 40.0

2 26.9 32.0 35.6 37.0 41.9

3 27.4 32.9 35.1 36.4 41.0

Avg. 27.4 32.8 35.6 37.1 41.0

SD 0.5 0.8 0.5 0.8 1.0

COV(%) 1.8 2.3 1.3 2.2 2.3

GU-3µm

1 31.3 34.8 36.0 38.9 41.6

2 31.6 34.6 36.5 37.0 40.0

3 31.0 34.9 35.5 38.3 41.3

Avg. 31.3 34.8 36.0 38.1 41.0

SD 0.3 0.2 0.5 1.0 0.9

COV(%) 1.0 0.4 1.4 2.6 2.1

HE

1 31.9 36.0 38.0 39.0 42.0

2 31.0 34.0 36.5 39.5 40.9

3 32.0 35.3 36.9 38.5 41.0

Avg. 31.6 35.1 37.1 39.0 41.3

SD 0.6 1.0 0.8 0.5 0.6

COV(%) 1.7 2.9 2.1 1.3 1.5

HE-17µm

1 33.9 35.9 36.7 38.9 41.0

2 32.3 35.0 38.0 40.0 40.0

3 33.9 35.4 37.0 37.8 40.9

Avg. 33.4 35.4 37.2 38.9 40.6

SD 0.9 0.5 0.7 1.1 0.6

COV(%) 2.8 1.3 1.8 2.8 1.4

HE-3µm

1 35.1 37.0 38.4 40.8 41.7

2 34.9 36.0 39.0 39.0 41.0

3 33.1 35.4 37.8 39.4 42.0

Avg. 34.4 36.1 38.4 39.7 41.6

SD 1.1 0.8 0.6 1.0 0.5

COV(%) 3.2 2.2 1.6 2.4 1.2

182

Table A.22: Hardened Density of Concrete Steam Cured at 55°C

Mix ID Sample # Density (kg/m3)


GU

1 2360 2360 2370 2370 2380

2 2350 2341 2355 2360 2380

3 2356 2340 2330 2350 2365

Avg. 2355 2347 2352 2360 2375

SD 5.0 11.3 20.2 10.0 8.7

COV(%) 0.2 0.5 0.9 0.4 0.4

GU-17µm

1 2370 2350 2360 2360 2390

2 2380 2340 2350 2340 2380

3 2330 2345 2357 2360 2380

Avg. 2360 2345 2356 2353 2383

SD 26.5 5.0 5.1 11.6 5.8

COV(%) 1.1 0.2 0.2 0.5 0.2

GU-3µm

1 2470 2460 2450 2470 2460

2 2460 2470 2440 2455 2460

3 2400 2460 2430 2440 2450

Avg. 2443 2463 2440 2455 2457

SD 37.9 5.8 10.0 15.0 5.8

COV(%) 1.6 0.2 0.4 0.6 0.2

HE

1 2400 2445 2430 2445 2420

2 2415 2400 2465 2400 2400

3 2400 2400 2400 2400 2470

Avg. 2405 2415 2432 2415 2430

SD 8.7 26.0 32.5 26.0 36.1

COV(%) 0.4 1.1 1.3 1.1 1.5

HE-17µm

1 2420 2445 2460 2480 2430

2 2430 2410 2430 2450 2450

3 2410 2390 2400 2400 2440

Avg. 2420 2415 2430 2443 2440

SD 10.0 27.8 30.0 40.4 10.0

COV(%) 0.4 1.2 1.2 1.7 0.4

HE-3µm

1 2460 2460 2450 2450 2470

2 2460 2470 2460 2445 2450

3 2450 2450 2440 2445 2460

Avg. 2457 2460 2450 2447 2460

SD 5.8 10.0 10.0 2.9 10.0

COV(%) 0.2 0.4 0.4 0.1 0.4

183

Table A.23: Compressive Strength of Concrete Steam Cured at 55°C

Mix ID Sample # Compressive Strength (MPa)

12 hrs. 16 hrs. 3 days 7 days 28 days 300 days

GU

1 38.8 48.6 60.2 65.3 72.6 88.0

2 37.0 46.9 57.9 63.6 71.1 90.4

3 37.8 47.9 58.7 64.5 73.8 89.6

Avg. 37.9 47.8 58.9 64.5 72.5 89.3

SD 0.9 0.9 1.2 0.9 1.4 1.2

COV(%) 2.4 1.8 2.0 1.3 1.9 1.4

GU-17µm

1 38.9 51.3 60.4 63.1 70.2 85.7

2 39.6 48.9 59.5 61.2 68.4 82.8

3 39.0 49.7 58.1 62.2 69.0 83.0

Avg. 39.2 50.0 59.3 62.2 69.2 83.8

SD 0.4 1.2 1.2 1.0 0.9 1.6

COV(%) 1.0 2.4 2.0 1.5 1.3 1.9

GU-3µm

1 46.0 56.9 63.8 66.8 74.7 87.6

2 44.4 55.3 60.0 64.4 71.8 84.5

3 46.0 53.9 62.0 66.4 73.4 85.6

Avg. 45.5 55.4 61.9 65.9 73.3 85.9

SD 0.9 1.5 1.9 1.3 1.5 1.6

COV(%) 2.0 2.7 3.1 2.0 2.0 1.8

HE

1 52.4 60.5 66.5 66.7 73.7 84.4

2 53.6 56.7 64.6 68.0 70.3 88.6

3 53.0 57.6 62.1 69.2 69.9 85.0

Avg. 53.0 58.3 64.4 68.0 71.3 86.0

SD 0.6 2.0 2.2 1.3 2.1 2.3

COV(%) 1.1 3.4 3.4 1.8 2.9 2.6

HE-17µm

1 53.0 54.6 63.6 67.7 70.1 83.5

2 51.0 57.7 63.6 64.6 70.1 80.6

3 51.2 56.4 60.6 66.4 73.2 82.3

Avg. 51.7 56.2 62.6 66.2 71.1 82.1

SD 1.1 1.6 1.7 1.5 1.8 1.5

COV(%) 2.1 2.8 2.8 2.3 2.6 1.8

HE-3µm

1 55.1 58.6 62.1 69.6 74.6 85.5

2 54.0 59.0 62.8 69.3 70.7 82.0

3 54.0 62.5 66.4 66.4 72.0 84.2

Avg. 54.4 60.0 63.8 68.4 72.4 83.9

SD 0.6 2.2 2.3 1.8 2.0 1.8

COV(%) 1.2 3.6 3.6 2.6 2.7 2.1

184

Table A.23 (Continued): Compressive Strength of Concrete Steam Cured at 55°C


16 hrs. 3 days 7 days 28 days 300 days

GUL

1 54.3 61.2 64.6 72.9 86.1

2 54.3 61.2 64.6 69.4 86.0

3 57.4 58.0 67.9 71.0 82.6

Avg. 55.3 60.1 65.7 71.1 84.9

SD 1.8 1.9 1.9 1.8 2.0

COV(%) 3.3 3.1 2.9 2.5 2.3

HS

1 50.5 57.8 67.1 70.4 86.0

2 48.0 57.8 67.1 70.4 82.4

3 49.6 60.7 64.1 73.5 84.5

Avg. 49.4 58.8 66.1 71.4 84.3

SD 1.3 1.7 1.7 1.8 1.8

COV(%) 2.6 2.8 2.6 2.5 2.1

HS-17µm

1 51.2 61.6 67.0 70.3 85.6

2 48.6 58.8 67.0 70.3 82.1

3 50.2 60.4 70.1 73.4 84.1

Avg. 50.0 60.2 68.0 71.3 83.9

SD 1.3 1.4 1.8 1.8 1.8

COV(%) 2.6 2.3 2.6 2.6 2.1

HS-3µm

1 52.0 59.4 68.9 75.0 88.6

2 52.0 59.4 65.8 71.6 85.5

3 55.1 62.6 67.4 73.6 86.5

Avg. 53.0 60.5 67.4 73.4 86.9

SD 1.8 1.9 1.6 1.7 1.6

COV(%) 3.4 3.1 2.3 2.3 1.8

185




GU

1 60.8 61.7 67.1 71.2 84.1

2 58.4 61.7 64.6 68.7 81.5

3 60.0 64.3 66.2 70.3 83.1

Avg. 59.7 62.6 66.0 70.1 82.9

SD 1.2 1.5 1.3 1.3 1.3

COV(%) 2.1 2.4 1.9 1.8 1.6

GU-17µm

1 62.3 62.8 66.2 69.5 80.6

2 59.8 62.8 63.6 69.5 80.6

3 61.4 65.6 65.2 66.7 77.6

Avg. 61.2 63.7 65.0 68.6 79.6

SD 1.3 1.6 1.3 1.6 1.7

COV(%) 2.1 2.5 2.0 2.4 2.2

GU-3µm

1 63.7 63.0 68.5 72.2 82.1

2 61.0 63.0 65.8 72.2 79.5

3 62.6 65.9 67.4 69.2 81.1

Avg. 62.4 64.0 67.2 71.2 80.9

SD 1.4 1.7 1.4 1.7 1.3

COV(%) 2.2 2.6 2.1 2.4 1.6

HE

1 63.8 68.0 67.1 68.0 84.1

2 59.6 66.5 67.0 72.1 80.1

3 61.0 64.3 70.5 70.0 81.5

Avg. 61.5 66.3 68.2 70.0 81.9

SD 2.1 1.9 2.0 2.1 2.1

COV(%) 3.5 2.8 2.9 2.9 2.5

HE-17µm

1 61.4 63.4 67.4 67.3 80.5

2 58.6 63.4 67.4 67.3 77.0

3 60.2 66.4 64.3 70.4 79.0

Avg. 60.0 64.4 66.3 68.3 78.8

SD 1.4 1.8 1.8 1.8 1.7

COV(%) 2.3 2.7 2.7 2.6 2.2

186




HE-3µm

1 64.2 69.2 67.0 74.5 80.0

2 60.1 68.2 67.8 70.1 76.0

3 62.4 65.1 71.5 72.3 77.7

Avg. 62.2 67.5 68.8 72.3 77.9

SD 2.0 2.1 2.4 2.2 2.0

COV(%) 3.3 3.2 3.5 3.0 2.6

GUL

1 62.0 64.0 65.1 69.4 80.0

2 58.5 61.0 65.1 69.0 80.0

3 60.6 62.6 68.4 72.8 83.0

Avg. 60.4 62.5 66.2 70.4 81.0

SD 1.8 1.5 1.9 2.1 1.7

COV(%) 2.9 2.5 2.9 3.0 2.2

HS

1 58.6 64.4 67.0 72.8 81.9

2 55.9 64.4 70.0 72.6 78.9

3 57.5 67.4 70.0 75.9 80.1

Avg. 57.3 65.4 69.0 73.8 80.3

SD 1.3 1.7 1.7 1.9 1.5

COV(%) 2.3 2.6 2.5 2.5 1.9

HS-17µm

1 59.3 62.3 68.6 73.1 77.7

2 56.6 65.1 71.5 72.7 80.4

3 58.2 63.9 70.2 69.9 79.3

Avg. 58.0 63.8 70.1 71.9 79.1

SD 1.4 1.4 1.5 1.7 1.4

COV(%) 2.4 2.2 2.1 2.4 1.7

HS-3µm

1 61.7 66.0 67.0 70.6 76.1

2 58.0 69.1 70.6 70.6 79.7

3 60.2 67.1 69.0 74.0 78.2

Avg. 60.0 67.4 68.9 71.7 78.0

SD 1.9 1.6 1.8 2.0 1.8

COV(%) 3.1 2.4 2.6 2.7 2.3

187




GU

1 71.5 71.2 71.5 72.8 79.3

2 69.0 72.1 71.9 73.7 80.7

3 70.6 69.6 74.2 71.2 82.1

Avg. 70.4 71.0 72.5 72.6 80.7

SD 1.3 1.3 1.5 1.3 1.4

COV(%) 1.8 1.8 2.0 1.8 1.7

GU-17µm

1 69.6 71.2 70.0 71.5 82.3

2 70.6 68.6 70.4 72.6 82.3

3 68.0 70.2 72.9 69.9 79.3

Avg. 69.4 70.0 71.1 71.3 81.3

SD 1.3 1.3 1.5 1.3 1.7

COV(%) 1.9 1.9 2.2 1.9 2.1

GU-3µm

1 70.0 73.3 73.5 75.5 83.4

2 70.0 70.5 74.7 72.7 84.8

3 73.0 72.1 71.9 74.3 81.8

Avg. 71.0 72.0 73.4 74.2 83.3

SD 1.7 1.4 1.4 1.4 1.5

COV(%) 2.4 2.0 1.9 1.9 1.8

HE

1 70.1 73.3 72.0 76.0 81.0

2 72.5 70.0 72.0 75.0 77.7

3 68.3 70.9 76.1 72.0 79.0

Avg. 70.3 71.4 73.4 74.3 79.2

SD 2.1 1.7 2.4 2.1 1.7

COV(%) 3.0 2.4 3.2 2.8 2.1

HE-17µm

1 65.8 70.5 72.3 71.6 78.0

2 65.8 67.6 72.2 71.0 75.5

3 68.9 69.2 69.2 74.6 77.1

Avg. 66.8 69.1 71.2 72.4 76.9

SD 1.8 1.5 1.8 1.9 1.3

COV(%) 2.7 2.1 2.5 2.6 1.7

188




HE-3µm

1 72.1 70.4 72.8 74.0 76.5

2 71.2 73.7 73.6 73.0 76.9

3 68.0 70.0 69.4 70.5 80.3

Avg. 70.4 71.4 71.9 72.5 77.9

SD 2.1 2.0 2.2 1.8 2.1

COV(%) 3.0 2.8 3.1 2.5 2.7

GUL

1 65.2 70.5 69.1 72.5 81.6

2 68.8 67.9 69.6 70.4 82.1

3 67.3 69.5 72.5 71.5 78.9

Avg. 67.1 69.3 70.4 71.5 80.9

SD 1.8 1.3 1.8 1.1 1.7

COV(%) 2.7 1.9 2.6 1.5 2.1

HS

1 68.4 66.4 69.2 71.6 78.0

2 65.6 69.2 69.2 74.5 81.0

3 67.2 68.0 72.3 73.3 79.6

Avg. 67.1 67.9 70.2 73.1 79.5

SD 1.4 1.4 1.8 1.5 1.5

COV(%) 2.1 2.1 2.5 2.0 1.9

HS-17µm

1 68.6 64.9 68.2 70.0 77.0

2 65.7 66.9 68.9 71.6 80.0

3 67.3 68.9 66.5 72.1 79.0

Avg. 67.2 66.9 67.9 71.2 78.7

SD 1.5 2.0 1.2 1.1 1.5

COV(%) 2.2 3.0 1.8 1.5 1.9

HS-3µm

1 68.4 66.7 70.1 70.1 82.0

2 69.2 67.0 70.8 73.1 82.0

3 65.7 70.4 67.4 72.4 79.0

Avg. 67.8 68.0 69.4 71.9 81.0

SD 1.8 2.0 1.8 1.6 1.7

COV(%) 2.7 3.0 2.6 2.2 2.2

189

Table A.26: UPV Results of Concrete Steam Cured at 55°C

Mix ID Sample # UPV (m/s)

12 hrs. 16 hrs. 3 days 7 days 28 days 300 days

GU

1 4200 4480 4600 4909 5130 5460

2 4230 4500 4720 4839 5180 5260

3 4200 4370 4700 4810 5001 5270

Avg. 4210 4450 4673 4853 5104 5330

SD 17 70.0 64.3 50.9 92.4 112.7

COV(%) 0.4 1.6 1.4 1.0 1.8 2.1

GU-17µm

1 4456 4624 4790 4772 5196 5330

2 4490 4690 4820 4780 5086 5490

3 4500 4790 4610 4810 4958 5416

Avg. 4482 4701 4740 4787 5080 5412

SD 23 83.6 113.6 20.0 119.1 80.1

COV(%) 0.5 1.8 2.4 0.4 2.3 1.5

GU-3µm

1 4700 4759 4920 5010 5120 5536

2 4680 4891 4900 4940 5080 5400

3 4706 4750 4850 4874 5340 5490

Avg. 4695 4800 4890 4941 5180 5475

SD 14 79.1 36.1 68.0 140.0 69.2

COV(%) 0.3 1.6 0.7 1.4 2.7 1.3

HE

1 4720 5000 4871 5020 5230 5300

2 4690 4910 5129 5080 5130 5330

3 4680 4850 4940 4962 5030 5240

Avg. 4697 4920 4980 5021 5130 5290

SD 21 75.5 134.0 59.0 100.0 45.8

COV(%) 0.4 1.5 2.7 1.2 1.9 0.9

HE-17µm

1 4850 4870 4903 4936 5190 5061

2 4770 5000 5120 5068 5120 5275

3 4780 5092 4976 5152 5005 5318

Avg. 4800 4987 5000 5052 5105 5218

SD 44 111.5 110.4 109.0 93.4 137.3

COV(%) 0.9 2.2 2.2 2.2 1.8 2.6

HE-3µm

1 4900 5000 5110 4990 5230 5243

2 4880 5120 5024 5259 5120 5300

3 4880 4880 5062 5069 5064 5312

Avg. 4887 5000 5065 5106 5138 5285

SD 12 120.0 43.1 138.4 84.5 37.1

COV(%) 0.2 2.4 0.9 2.7 1.6 0.7

190

Table A.26 (Continued): UPV Results of Concrete Steam Cured at 55°C



HE-3µm

1 5000 5110 4990 5230 5243

2 5120 5024 5259 5120 5300

3 4880 5062 5069 5064 5312

Avg. 5000 5065 5106 5138 5285

SD 120.0 43.1 138.4 84.5 37.1

COV(%) 2.4 0.9 2.7 1.6 0.7

GUL

1 4702 4653 4830 5000 5214

2 4640 4700 4720 5030 5326

3 4736 4747 4816 5120 5420

Avg. 4693 4700 4789 5050 5320

SD 48.7 47.0 59.9 62.4 103.3

COV(%) 1.0 1.0 1.3 1.2 1.9

HS

1 4840 4740 4831 5000 5290

2 4700 4884 4919 5010 5410

3 4662 4812 4950 5046 5484

Avg. 4734 4812 4900 5019 5395

SD 93.7 72.2 61.4 24.2 97.9

COV(%) 2.0 1.5 1.3 0.5 1.8

HS-17µm

1 4680 4840 4685 5090 5073

2 4616 4730 5010 5000 5315

3 4730 4770 4855 4956 5254

Avg. 4675 4780 4850 5015 5214

SD 57.1 55.7 162.5 68.3 125.6

COV(%) 1.2 1.2 3.4 1.4 2.4

HS-3µm

1 4523 4640 4838 5020 5016

2 4641 4670 4700 4950 5320

3 4612 4610 4710 4880 5243

Avg. 4592 4640 4749 4950 5193

SD 61.4 30.0 77.0 70.0 157.6

COV(%) 1.3 0.6 1.6 1.4 3.0

191




GU

1 4733 4812 4820 5100 5430

2 4567 4826 4800 5056 5339

3 4617 4618 5011 4958 5221

Avg. 4639 4752 4877 5038 5330

SD 85.2 116.3 116.5 72.7 104.8

COV(%) 1.8 2.4 2.4 1.4 2.0

GU-17µm

1 4768 4790 4978 5180 5489

2 4654 4867 4900 5000 5304

3 4684 4710 4711 5126 5197

Avg. 4702 4789 4863 5102 5330

SD 59.1 78.5 137.3 92.4 147.7

COV(%) 1.3 1.6 2.8 1.8 2.8

GU-3µm

1 4839 4698 4950 5000 5120

2 4678 4856 4900 4910 5340

3 4589 4891 4853 5015 5530

Avg. 4702 4815 4901 4975 5330

SD 126.7 102.8 48.5 56.8 205.2

COV(%) 2.7 2.1 1.0 1.1 3.8

HE

1 4834 4856 4812 4910 5179

2 4745 4734 4800 5003 5189

3 4527 4660 4824 4976 5211

Avg. 4702 4750 4812 4963 5193

SD 158.0 99.0 12.0 47.8 16.4

COV(%) 3.4 2.1 0.2 1.0 0.3

HE-17µm

1 4720 4870 4890 5000 5200

2 4730 4750 4820 4924 5120

3 4590 4630 4840 5001 5148

Avg. 4680 4750 4850 4975 5156

SD 78.1 120.0 36.1 44.2 40.6

COV(%) 1.7 2.5 0.7 0.9 0.8

192




HE-3µm

1 4768 4869 4898 4900 5300

2 4656 4759 4800 4887 5230

3 4676 4766 4765 4916 5142

Avg. 4700 4798 4821 4901 5224

SD 59.7 61.6 68.9 14.5 79.2

COV(%) 1.3 1.3 1.4 0.3 1.5

GUL

1 4830 4812 4900 5000 5390

2 4745 4889 4845 4967 5249

3 4681 4849 4895 4973 5264

Avg. 4752 4850 4880 4980 5301

SD 74.7 38.5 30.4 17.6 77.4

COV(%) 1.6 0.8 0.6 0.4 1.5

HS

1 4580 4638 4730 5000 5400

2 4434 4600 4600 4978 5389

3 4585 4559 4725 5007 5255

Avg. 4533 4599 4685 4995 5348

SD 85.8 39.5 73.7 15.1 80.7

COV(%) 1.9 0.9 1.6 0.3 1.5

HS-17µm

1 4500 4700 4967 5023 5400

2 4400 4750 4800 4900 5340

3 4567 4617 4858 5038 5232

Avg. 4489 4689 4875 4987 5324

SD 84.0 67.2 84.8 75.7 85.1

COV(%) 1.9 1.4 1.7 1.5 1.6

HS-3µm

1 4489 4789 4835 4976 5400

2 4387 4656 4658 4800 5200

3 4396 4622 4853 4894 5024

Avg. 4424 4689 4782 4890 5208

SD 56.5 88.3 107.8 88.1 188.1

COV(%) 1.3 1.9 2.3 1.8 3.6

193




GU

1 4800 4890 5000 5000 5438

2 4723 4800 4900 4967 5398

3 4679 4860 4803 5033 5238

Avg. 4734 4850 4901 5000 5358

SD 61.2 45.8 98.5 33.0 105.8

COV(%) 1.3 0.9 2.0 0.7 2.0

GU-17µm

1 4930 4812 4965 5000 5400

2 4800 4857 4834 5012 5349

3 4676 4731 4904 5180 5454

Avg. 4802 4800 4901 5064 5401

SD 127.0 63.9 65.6 100.6 52.5

COV(%) 2.6 1.3 1.3 2.0 1.0

GU-3µm

1 4949 4978 5000 5234 5500

2 4800 4857 4923 5100 5400

3 4954 4865 4891 5092 5522

Avg. 4901 4900 4938 5142 5474

SD 87.5 67.7 56.0 79.8 65.0

COV(%) 1.8 1.4 1.1 1.6 1.2

HE

1 4756 4834 4800 5000 5156

2 4700 4800 4834 4998 5180

3 4665 4733 4985 5038 5243

Avg. 4707 4789 4873 5012 5193

SD 45.9 51.4 98.5 22.5 44.9

COV(%) 1.0 1.1 2.0 0.4 0.9

HE-17µm

1 4800 4890 4900 5000 5300

2 4750 4800 4967 5046 5278

3 4856 4944 4845 4954 5292

Avg. 4802 4878 4904 5000 5290

SD 53.0 72.7 61.1 46.0 11.1

COV(%) 1.1 1.5 1.2 0.9 0.2

194




HE-3µm

1 4712 4778 4854 5000 5323

2 4790 4756 4776 4923 5200

3 4874 4836 4992 5038 5194

Avg. 4792 4790 4874 4987 5239

SD 81.0 41.3 109.4 58.6 72.8

COV(%) 1.7 0.9 2.2 1.2 1.4

GUL

1 4734 4800 4900 5000 5312

2 4770 4900 4967 4978 5234

3 4638 4700 4803 5022 5312

Avg. 4714 4800 4890 5000 5286

SD 68.2 100.0 82.5 22.0 45.0

COV(%) 1.4 2.1 1.7 0.4 0.9

HS

1 4510 4700 4812 5000 5320

2 4595 4600 4790 4900 5123

3 4656 4761 4753 5022 5136

Avg. 4587 4687 4785 4974 5193

SD 73.3 81.3 29.8 65.0 110.2

COV(%) 1.6 1.7 0.6 1.3 2.1

HS-17µm

1 4600 4723 4857 4956 5120

2 4690 4756 4812 4800 5200

3 4546 4615 4686 4815 5247

Avg. 4612 4698 4785 4857 5189

SD 72.7 73.7 88.6 86.1 64.2

COV(%) 1.6 1.6 1.9 1.8 1.2

HS-3µm

1 4690 4698 4856 4956 5320

2 4600 4734 4700 4980 5200

3 4696 4923 4793 4680 5185

Avg. 4662 4785 4783 4872 5235

SD 53.8 120.9 78.5 166.7 74.0

COV(%) 1.2 2.5 1.6 3.4 1.4

195

A.7.4 Transport Properties of Concrete

Table A.29: Rapid Chloride Permeability Values of Concrete at 28 Days

Mix ID Steam Curing

Temp.

RCPT (Coulombs)

Sample # Average SD COV (%)

1 2 3

GU

55°C

598 638 612 616 20 3.3

GU-17µm 442 437 446 442 5 1.0

GU-3µm 415 409 409 411 3 0.8

HE 455 466 494 472 20 4.3

HE-17µm 408 368 388 388 20 5.2

HE-3µm 330 350 310 330 20 6.1

GUL 760 700 685 715 40 5.6

HS 600 649 581 610 35 5.8

HS-17µm 580 600 590 590 10 1.7

HS-3µm 530 534 556 540 14 2.6

GU

70°C

1010 1080 1060 1050 36 3.4

GU-17µm 1000 940 983.5 975 31 3.2

GU-3µm 830 875 860 855 23 2.7

HE 926 990 1037.5 985 56 5.7

HE-17µm 1100 997 1008 1035 57 5.5

HE-3µm 900 923 991 938 47 5.0

GUL 1140 1049 1129 1106 50 4.5

HS 1230 1212 1323 1255 60 4.7

HS-17µm 1230 1198 1172 1200 29 2.4

HS-3µm 1175 1110 1168 1151 36 3.1

GU

82°C

1130 1189 1168.5 1163 30 2.6

GU-17µm 1069 1011 1115 1065 52 4.9

GU-3µm 945 978 985.5 970 22 2.2

HE 1150 1100 1066.5 1106 42 3.8

HE-17µm 1167 1120 1053.5 1114 57 5.1

HE-3µm 1000 1030 1120 1050 62 5.9

GUL 1279 1253 1152 1228 67 5.5

HS 1492 1367 1443 1434 63 4.4

HS-17µm 1311 1369 1370 1350 34 2.5

HS-3µm 1336 1356 1278.5 1324 40 3.0

196

Table A.30: Rapid Chloride Permeability Values of Concrete at 300 Days

Mix ID Steam Curing

Temp.

RCPT (Coulombs)

Sample # Average SD COV (%)

1 2 3

GU

55°C

490 470 480 480 10 2.1

GU-17µm 400 420 386 402 17 4.3

GU-3µm 200 198 199 199 1 0.5

HE 412 410 378 400 19 4.8

HE-17µm 324 360 366 350 23 6.5

HE-3µm 279 300 321 300 21 7.0

GUL 511 515 555 527 24 4.6

HS 570 540 516 542 27 5.0

HS-17µm 515 490 495 500 13 2.6

HS-3µm 460 440 444 448 11 2.4

GU

70°C

870 866 814 850 31 3.7

GU-17µm 867 814 896 859 42 4.8

GU-3µm 630 640 629 633 6 1.0

HE 889 860 822 857 34 3.9

HE-17µm 790 839 738 789 51 6.4

HE-3µm 550 600 569 573 25 4.4

GUL 690 710 640 680 36 5.3

HS 800 760 831 797 36 4.5

HS-17µm 770 730 765 755 22 2.9

HS-3µm 798 765 792 785 18 2.2

GU

82°C

927 900 915 914 14 1.5

GU-17µm 800 843 793 812 27 3.3

GU-3µm 744 732 732 736 7 0.9

HE 1000 1040 948 996 46 4.6

HE-17µm 820 840 728 796 60 7.5

HE-3µm 690 630 687 669 34 5.1

GUL 819 790 731 780 45 5.7

HS 1078 1000 1069 1049 43 4.1

HS-17µm 879 830 838 849 26 3.1

HS-3µm 717 711 672 700 24 3.5

197

A.7.5 Durability Performance of Concrete/Mortar

Table A.31: Linear Shrinkage of Concrete Made of GU Cement

GU GU-17µm GU-3µm

Age

(Day)

Avg.

Shrinkage

(%)

SD COV

(%)

Age

(Day)

Avg.

Shrinkage

(%)

SD COV

(%)

Age

(Day)

Avg.

Shrinkage

(%)

SD COV

(%)

0 0.000 --- --- 0 0.000 --- --- 0.0 0.000 --- ---

2 0.005 0.002 0.3 4 0.009 0.001 6.7 1.0 0.002 0.000 5.0

3 0.008 0.001 5.7 5 0.010 0.006 0.5 2.5 0.004 0.001 0.3

7 0.013 0.007 0.5 7 0.013 0.001 4.8 6.5 0.009 0.000 1.1

8 0.014 0.001 4.8 11 0.016 0.007 0.5 9.8 0.012 0.002 0.2

9 0.015 0.007 0.4 14 0.017 0.000 1.8 14.3 0.016 0.000 1.4

13 0.018 0.001 3.2 18 0.018 0.004 0.2 16.8 0.017 0.004 0.2

17 0.020 0.007 0.3 21 0.019 0.001 4.7 21.9 0.018 0.000 1.7

21 0.022 0.001 4.3 26 0.020 0.007 0.3 29.0 0.019 0.004 0.2

24 0.023 0.008 0.3 33 0.022 0.001 3.7 63.3 0.022 0.001 4.6

29 0.024 0.001 3.6 67 0.025 0.006 0.2

36 0.025 0.000 3.8

70 0.028 0.007 0.2

Table A.32: Linear Shrinkage of Concrete Made of HE Cement

HE HE-17µm HE-3µm

Age

(Days)

Avg.

Shrinkage

(%)

SD COV

(%)

Age

(Days

Avg.

Shrinkage

(%)

SD COV

(%)

Age

(Days

Avg.

Shrinkage

(%)

SD COV

(%)

0 0.000 --- --- 0 0.000 --- --- 0 0.000 --- ---

2 0.005 0.000 2.1 1 0.003 0.000 3.3 2 0.005 0.000 8.0

6 0.009 0.004 0.5 3 0.006 0.007 1.1 6 0.010 0.001 0.1

13 0.016 0.001 5.4 7 0.011 0.000 3.4 9 0.012 0.001 5.0

16 0.017 0.006 0.4 10 0.013 0.003 0.2 14 0.015 0.006 0.4

21 0.019 0.000 2.1 15 0.016 0.001 6.3 21 0.017 0.001 3.5

28 0.021 0.007 0.4 22 0.019 0.003 0.1 55 0.021 0.004 0.2

62 0.024 0.001 2.5 56 0.023 0.002 7.8

198

Table A.33: Sulfate Resistance of Mortar Made of GU Cement

Age

(Weeks)

GU GU-17µm GU-3µm

Average

Expansion

(%)

SD COV

(%)

Average

Expansion

(%)

SD COV

(%)

Average

Expansion

(%)

SD COV

(%)

0.0 0.000 --- --- 0.000 --- --- 0.000 --- ---

0.9 0.013 0.0015 11.5 0.015 0.0013 8.2 0.016 0.0009 5.4

2.0 0.015 0.0010 6.7 0.019 0.0014 8.3 0.019 0.0005 2.6

3.0 0.018 0.0004 1.9 0.021 0.0019 9.2 0.021 0.0007 3.4

4.0 0.020 0.0007 4.5 0.022 0.0025 13.2 0.022 0.0008 3.8

6.0 0.023 0.0006 2.8 0.024 0.0025 10.4 0.025 0.0009 3.8

10.9 0.026 0.0003 1.1 0.028 0.0023 8.3 0.029 0.0007 2.4

12.9 0.027 0.0005 1.7 0.030 0.0019 6.3 0.031 0.0009 2.8

16.9 0.028 0.0008 2.7 0.03 0.0028 9.2 0.0315 0.0003 1.0

18.3 0.029 0.0008 2.2 0.030 0.0032 8.5 0.032 0.0011 2.7

23.3 0.036 0.0015 11.5 0.037 0.0013 8.2 0.039 0.0009 5.4

25.3 0.040 0.0007 1.8 0.041 0.0013 3.2 0.042 0.0005 1.2

Table A.34: Sulfate Resistance of Mortar Made of HE Cement

Age

(Weeks)

HE HE -17µm HE -3µm

Average

Expansion

(%)

SD COV

(%)

Average

Expansion

(%)

SD COV

(%)

Average

Expansion

(%)

SD COV

(%)

0.0 0.000 --- --- 0.000 --- --- 0.000 --- ---

0.9 0.007 0.0009 12.8 0.010 0.0012 12.7 0.009 0.0008 8.9

2.0 0.007 0.0008 12.3 0.009 0.0011 12.1 0.008 0.0008 9.7

3.0 0.014 0.0015 10.8 0.016 0.0015 9.5 0.015 0.0004 2.7

4.7 0.015 0.0012 8.4 0.017 0.0017 10.0 0.016 0.0010 6.0

6.6 0.018 0.0012 6.9 0.020 0.0021 10.7 0.019 0.0006 3.2

8.0 0.021 0.0013 6.5 0.022 0.0024 10.8 0.021 0.0010 4.7

10.0 0.022 0.0014 6.4 0.024 0.0016 6.6 0.022 0.0012 5.5

12.0 0.021 0.0016 7.5 0.024 0.0017 7.0 0.022 0.0012 5.4

13.0 0.023 0.0015 6.7 0.025 0.0017 6.5 0.024 0.0010 4.3

17.9 0.028 0.0016 5.5 0.031 0.0021 6.8 0.029 0.0010 3.6

19.9 0.029 0.0014 4.8 0.031 0.0022 7.0 0.029 0.0010 3.6

199

Table A.35: Salt Scaling of Concrete

Mix ID Specimens # Mass Loss (kg/m2) after 50 Freeze-Thaw Cycles

GU

1 0.018

2 0.019

Avg. 0.019

GU-17µm

1 0.447

2 0.440

Avg. 0.444

GU-3µm

1 0.369

2 0.384

Avg. 0.376

HE

1 0.249

2 0.256

Avg. 0.253

HE-17µm

1 0.195

2 0.201

Avg. 0.198

HE-3µm

1 0.213

2 0.195

Avg. 0.204

200

Table A.36: Freeze-Thaw Resistance of Concrete

(75 mm × 75 mm × 285 mm Prisms- Tested in Chapter 4)

Mix ID Specimens # Length Change (%) Durability Factor (%)

GU

1 0.0115 98.3

2 0.0105 97.6

Avg. 0.0110 98.0

GU-17µm

1 0.0129 98.5

2 0.0135 97.6

Avg. 0.0132 98.1

GU-3µm

1 0.0119 98.1

2 0.0121 97.7

Avg. 0.0120 97.9

HE

1 0.0119 99.5

2 0.0121 98.5

Avg. 0.0120 99.0

HE-17µm

1 0.0165 97.5

2 0.0168 96.5

Avg. 0.0167 97.0

HE-3µm

1 0.0165 97.2

2 0.0168 96.9

Avg. 0.0167 97.1

201

Table A.37: Freeze-Thaw Resistance of Concrete

(50 mm × 50 mm × 285 mm Prisms- Tested in Chapter 5)

Mix ID

Steam

Curing

Temp.

Freeze-Thaw Durability Factor (%)

Sample # Average SD

COV

(%) 1 2 3

GU

55°C

97.0 98.0 99.0 98.0 1.0 1.0

GU-17µm 97.5 96.0 99.0 97.5 1.5 1.5

GU-3µm 98.2 98.0 99.6 98.6 0.9 0.9

HE 98.4 97.3 97.7 97.8 0.6 0.6

HE-17µm 96.3 95.8 97.1 96.4 0.7 0.7

HE-3µm 98.5 98.1 99.5 98.7 0.7 0.7

GUL 97.3 96.8 97.2 97.1 0.3 0.3

HS 98.5 98.0 98.1 98.2 0.3 0.3

HS-17µm 97.5 96.5 93.7 95.9 2.0 2.1

HS-3µm 97.3 95.1 96.2 96.2 1.1 1.1

GU

70°C

67.5 67.9 69.8 68.4 1.2 1.8

GU-17µm 79.2 82.4 79.3 80.3 1.8 2.3

GU-3µm 78.9 77.2 81.5 79.2 2.2 2.7

HE 81.4 79.1 82.8 81.1 1.9 2.3

HE-17µm 85.4 81.3 82.9 83.2 2.1 2.5

HE-3µm 87.8 82.3 84.0 84.7 2.8 3.3

GUL 81.4 83.2 81.7 82.1 1.0 1.2

HS 96.2 94.2 94.9 95.1 1.0 1.1

HS-17µm 93.9 91.1 94.9 93.3 2.0 2.1

HS-3µm 95.7 92.1 95.4 94.4 2.0 2.1

GU

82°C

57.4 53.8 56.2 55.8 1.8 3.3

GU-17µm 69.9 67.9 69.8 69.2 1.1 1.6

GU-3µm 75.5 70.1 71.3 72.3 2.8 3.9

HE 65.9 60.4 63.6 63.3 2.8 4.4

HE-17µm 72.6 68.6 74.5 71.9 3.0 4.2

HE-3µm 75.6 68.0 71.5 71.7 3.8 5.3

GUL 74.9 71.3 72.8 73.0 1.8 2.5

HS 94.5 90.4 91.4 92.1 2.1 2.3

HS-17µm 96.7 91.1 94.2 94.0 2.8 3.0

HS-3µm 98.2 93.0 98.0 96.4 2.9 3.1

202

A.7.5.1 Concrete Expansion

In this section, the expansion curves of concrete during the water immersion for 300 days

are presented. In addition, this section presents the raw data of concrete expansion up to

300 days.

A.7.5.1.1 Effect of Limestone Filler

In this section, the expansions of concrete mixes made with LF are compared to the

expansion of concrete mixes made without LF at different steam curing temperature, as

presented in Figures A.4 to A.9.

Figure A.4: Effect of 17µm LF on the Expansion of Concrete made of GU Cement

0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)

GU-55°C GU-70°C GU-82°C

GU-17µm-55°C GU-17µm-70°C GU-17µm-82°C

203

Figure A.5: Effect of 3µm LF on the Expansion of Concrete made of GU Cement

Figure A.6: Effect of 17µm LF on the Expansion of Concrete made of HE Cement

0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)

GU-55°C GU-70°C GU-82°C


0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)

HE-55°C HE-70°C HE-82°C

HE-17µm-55°C HE-17µm-70°C HE-17µm-82°C

204

Figure A.7: Effect of 3µm LF on the Expansion of Concrete made of HE Cement

Figure A.8: Effect of 17µm LF on the Expansion of Concrete made of HS Cement

0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)

HE-55°C HE-70°C HE-82°C

HE-3µm-55°C HE-3µm-70°C HE-3µm-82°C

0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)

HS-55°C HS-70°C HS-82°C

HS-17µm-55°C HS-17µm-70°C HS-17µm-82°C

205

Figure A.9: Effect of 3µm LF on the Expansion of Concrete made of HS Cement

A.7.5.1.2 Effect of Intergrinding Versus Blending of Limestone

In this section, the expansion of concrete mixture made of GUL cement is compared to the

expansion of concrete mixes made of GU cement blended with LF of 17µm and 3µm, as

presented in Figure A.10.

Figure A.10: Effect of Intergrinding and Blending LF on Concrete Expansion

0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)

HS-55°C HS-70°C HS-82°C

HS-3µm-55°C HS-3µm-70°C HS-3µm-82°C

0.00

0.01

0.02

0.03

0.04

0.05

0 50 100 150 200 250 300

Exp

ansi

on (

%)

Age (Days)



GUL-55°C GUL-70°C GUL-82°C

206

Table A.38: Concrete Expansion of Mix GU


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

14 0.005 0.006 0.007 0.006 14 0.017 0.019 0.021 0.019 9 0.019 0.02 0.021 0.02

30 0.006 0.007 0.008 0.007 28 0.02 0.022 0.024 0.022 25 0.022 0.023 0.024 0.023

42 0.007 0.008 0.009 0.008 46 0.022 0.024 0.026 0.024 41 0.024 0.025 0.026 0.025

56 0.008 0.009 0.01 0.009 60 0.023 0.026 0.029 0.026 55 0.027 0.028 0.029 0.028

80 0.009 0.010 0.011 0.010 76 0.025 0.028 0.031 0.028 71 0.029 0.03 0.031 0.030

100 0.010 0.011 0.012 0.011 90 0.026 0.029 0.032 0.029 85 0.03 0.031 0.032 0.031

119 0.011 0.012 0.013 0.012 110 0.027 0.03 0.033 0.030 100 0.031 0.032 0.033 0.032

140 0.011 0.012 0.013 0.012 133 0.029 0.032 0.035 0.032 114 0.033 0.034 0.035 0.034

160 0.012 0.013 0.014 0.013 150 0.03 0.033 0.036 0.033 128 0.034 0.035 0.036 0.035

180 0.012 0.013 0.014 0.013 165 0.032 0.035 0.039 0.035 145 0.036 0.037 0.038 0.037

198 0.012 0.013 0.014 0.013 180 0.032 0.036 0.040 0.036 160 0.037 0.038 0.039 0.038

214 0.012 0.013 0.014 0.013 200 0.033 0.037 0.041 0.037 175 0.038 0.039 0.04 0.039

228 0.012 0.013 0.014 0.013 228 0.035 0.039 0.043 0.039 195 0.04 0.041 0.042 0.041

245 0.013 0.014 0.015 0.014 258 0.035 0.039 0.043 0.039 223 0.041 0.042 0.043 0.042

260 0.013 0.014 0.015 0.014 287 0.036 0.04 0.044 0.040 253 0.042 0.043 0.044 0.043

280 0.014 0.015 0.016 0.015 300 0.036 0.04 0.044 0.040 282 0.042 0.043 0.044 0.043

300 0.014 0.015 0.016 0.015 --- --- --- --- --- 300 0.043 0.044 0.045 0.044

207

Table A.39: Concrete Expansion of Mix GU-17µm


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

14 0.006 0.006 0.006 0.006 14 0.017 0.017 0.020 0.018 9 0.020 0.020 0.020 0.020

30 0.007 0.007 0.007 0.007 30 0.020 0.020 0.023 0.021 25 0.023 0.023 0.023 0.023

45 0.008 0.008 0.008 0.008 46 0.022 0.022 0.025 0.023 41 0.024 0.024 0.024 0.024

60 0.009 0.009 0.009 0.009 61 0.024 0.024 0.027 0.025 56 0.026 0.026 0.026 0.026

74 0.010 0.010 0.010 0.010 76 0.026 0.026 0.029 0.027 71 0.027 0.027 0.027 0.027

89 0.011 0.011 0.011 0.011 91 0.027 0.027 0.03 0.028 86 0.029 0.029 0.029 0.029

103 0.011 0.011 0.011 0.011 106 0.028 0.028 0.031 0.029 100 0.030 0.030 0.030 0.030

119 0.011 0.011 0.011 0.011 121 0.029 0.029 0.032 0.030 114 0.031 0.031 0.031 0.031

133 0.012 0.012 0.012 0.012 133 0.030 0.030 0.033 0.031 128 0.032 0.032 0.032 0.032

148 0.012 0.012 0.012 0.012 148 0.030 0.030 0.033 0.031 142 0.034 0.034 0.034 0.034

163 0.012 0.012 0.012 0.012 165 0.030 0.030 0.033 0.031 160 0.036 0.036 0.036 0.036

198 0.012 0.012 0.012 0.012 200 0.031 0.031 0.034 0.032 195 0.039 0.039 0.039 0.039

212 0.012 0.012 0.012 0.012 228 0.033 0.033 0.036 0.034 223 0.040 0.040 0.040 0.040

227 0.012 0.012 0.012 0.012 258 0.035 0.035 0.038 0.036 253 0.041 0.041 0.041 0.041

240 0.013 0.013 0.013 0.013 287 0.036 0.036 0.039 0.037 282 0.042 0.042 0.042 0.042

254 0.013 0.013 0.013 0.013 300 0.036 0.036 0.039 0.037 300 0.042 0.042 0.042 0.042

280 0.013 0.013 0.013 0.013 --- --- --- --- --- --- --- --- --- ---

300 0.014 0.014 0.014 0.014 --- --- --- --- --- --- --- --- --- ---

208

Table A.40: Concrete Expansion of Mix GU-3µm


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

14 0.008 0.008 0.005 0.007 14 0.019 0.022 0.016 0.019 9 0.018 0.015 0.018 0.017

30 0.010 0.009 0.006 0.008 28 0.022 0.025 0.019 0.022 24 0.021 0.018 0.021 0.020

45 0.010 0.009 0.006 0.008 46 0.023 0.026 0.020 0.023 41 0.023 0.019 0.024 0.022

59 0.011 0.010 0.006 0.009 60 0.024 0.028 0.020 0.024 55 0.024 0.020 0.025 0.023

74 0.011 0.010 0.006 0.009 76 0.025 0.029 0.021 0.025 71 0.025 0.021 0.026 0.024

88 0.011 0.010 0.006 0.009 90 0.026 0.03 0.022 0.026 85 0.027 0.023 0.028 0.026

119 0.013 0.012 0.008 0.011 118 0.028 0.032 0.024 0.028 114 0.030 0.026 0.031 0.029

134 0.013 0.012 0.008 0.011 133 0.029 0.033 0.025 0.029 128 0.030 0.026 0.031 0.029

148 0.014 0.013 0.008 0.012 147 0.030 0.035 0.026 0.030 143 0.033 0.027 0.033 0.031

163 0.014 0.013 0.008 0.012 165 0.031 0.036 0.026 0.031 160 0.035 0.029 0.035 0.033

179 0.014 0.013 0.008 0.012 180 0.032 0.037 0.027 0.032 174 0.037 0.031 0.037 0.035

198 0.014 0.013 0.008 0.012 200 0.033 0.038 0.028 0.033 195 0.038 0.032 0.039 0.036

212 0.016 0.014 0.009 0.013 228 0.034 0.039 0.029 0.034 223 0.039 0.033 0.040 0.037

226 0.016 0.014 0.009 0.013 258 0.036 0.041 0.031 0.036 253 0.040 0.033 0.041 0.038

240 0.016 0.014 0.009 0.013 280 0.037 0.043 0.031 0.037 280 0.041 0.034 0.042 0.039

254 0.016 0.014 0.009 0.013 300 0.037 0.043 0.031 0.037 300 0.041 0.034 0.042 0.039

280 0.017 0.015 0.010 0.014 --- --- --- --- --- --- --- --- --- ---

300 0.017 0.015 0.010 0.014 --- --- --- --- --- --- --- --- --- ---

209

Table A.41: Concrete Expansion of Mix HE


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

14 0.007 0.006 0.008 0.007 14 0.019 0.018 0.015 0.017 8 0.014 0.015 0.016 0.015

30 0.008 0.007 0.009 0.008 30 0.024 0.023 0.019 0.022 25 0.021 0.022 0.023 0.022

45 0.009 0.008 0.010 0.009 46 0.025 0.024 0.020 0.023 40 0.022 0.023 0.024 0.023

60 0.009 0.008 0.010 0.009 60 0.026 0.025 0.021 0.024 55 0.024 0.025 0.026 0.025

75 0.010 0.009 0.011 0.010 76 0.027 0.026 0.022 0.025 70 0.026 0.027 0.028 0.027

100 0.010 0.009 0.011 0.010 90 0.028 0.027 0.023 0.026 95 0.028 0.029 0.030 0.029

119 0.011 0.01 0.012 0.011 114 0.029 0.028 0.023 0.027 100 0.029 0.03 0.032 0.030

135 0.012 0.011 0.013 0.012 133 0.031 0.029 0.024 0.028 114 0.030 0.031 0.033 0.031

150 0.013 0.012 0.014 0.013 150 0.032 0.03 0.025 0.029 127 0.030 0.031 0.033 0.031

175 0.013 0.012 0.014 0.013 165 0.034 0.032 0.027 0.031 142 0.031 0.032 0.034 0.032

198 0.013 0.012 0.014 0.013 180 0.034 0.032 0.027 0.031 159 0.033 0.034 0.036 0.034

214 0.013 0.012 0.014 0.013 200 0.034 0.032 0.027 0.031 180 0.034 0.035 0.037 0.035

228 0.014 0.013 0.015 0.014 214 0.035 0.033 0.028 0.032 208 0.035 0.036 0.038 0.036

245 0.014 0.013 0.015 0.014 228 0.036 0.034 0.029 0.033 222 0.036 0.037 0.039 0.037

260 0.014 0.013 0.015 0.014 242 0.037 0.035 0.030 0.034 236 0.036 0.037 0.039 0.037

300 0.015 0.014 0.016 0.015 258 0.038 0.036 0.030 0.035 252 0.036 0.038 0.040 0.038

--- --- --- --- --- 287 0.039 0.037 0.031 0.036 281 0.037 0.039 0.041 0.039

--- --- --- --- --- 300 0.039 0.037 0.031 0.036 300 0.037 0.039 0.041 0.039

210

Table A.42: Concrete Expansion of Mix HE-17µm


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

14 0.007 0.007 0.007 0.007 13 0.018 0.017 0.013 0.016 8 0.014 0.012 0.016 0.014

30 0.008 0.007 0.009 0.008 27 0.021 0.02 0.016 0.019 23 0.019 0.017 0.021 0.019

44 0.008 0.007 0.009 0.008 45 0.022 0.021 0.017 0.020 40 0.02 0.018 0.022 0.020

60 0.009 0.008 0.010 0.009 60 0.023 0.022 0.018 0.021 55 0.022 0.020 0.024 0.022

74 0.009 0.008 0.010 0.009 75 0.024 0.023 0.019 0.022 70 0.023 0.021 0.025 0.023

88 0.009 0.008 0.010 0.009 90 0.025 0.024 0.020 0.023 85 0.024 0.022 0.026 0.024

102 0.009 0.008 0.010 0.009 104 0.025 0.024 0.020 0.023 99 0.025 0.023 0.027 0.025

119 0.010 0.009 0.011 0.010 118 0.026 0.025 0.021 0.024 113 0.026 0.024 0.028 0.026

134 0.010 0.009 0.011 0.010 132 0.028 0.026 0.022 0.025 127 0.027 0.025 0.029 0.027

148 0.010 0.009 0.011 0.010 146 0.029 0.027 0.022 0.026 142 0.028 0.026 0.030 0.028

164 0.010 0.009 0.011 0.010 164 0.030 0.028 0.023 0.027 159 0.029 0.027 0.031 0.029

179 0.011 0.010 0.012 0.011 178 0.031 0.029 0.024 0.028 174 0.029 0.027 0.031 0.029

198 0.011 0.010 0.012 0.011 192 0.033 0.031 0.026 0.030 194 0.030 0.028 0.032 0.030

215 0.012 0.011 0.013 0.012 227 0.034 0.032 0.027 0.031 222 0.031 0.029 0.033 0.031

230 0.012 0.011 0.013 0.012 257 0.035 0.033 0.028 0.032 252 0.031 0.030 0.034 0.032

255 0.013 0.012 0.014 0.013 279 0.036 0.033 0.028 0.032 270 0.032 0.030 0.034 0.032

280 0.013 0.012 0.014 0.013 300 0.036 0.034 0.029 0.033 300 0.032 0.030 0.034 0.032

300 0.013 0.012 0.014 0.013 --- --- --- --- --- --- --- --- --- ---

211

Table A.43: Concrete Expansion of Mix HE-3µm


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0.000 0 0 0 0 0.000 0 0 0 0 0.000

14 0.009 0.008 0.005 0.007 13 0.020 0.015 0.016 0.017 8 0.013 0.015 0.017 0.015

30 0.010 0.009 0.006 0.008 27 0.022 0.017 0.018 0.019 23 0.016 0.019 0.022 0.019

44 0.010 0.009 0.006 0.008 45 0.023 0.018 0.019 0.020 40 0.017 0.020 0.023 0.020

60 0.011 0.010 0.006 0.009 60 0.025 0.019 0.020 0.021 55 0.019 0.022 0.025 0.022

74 0.011 0.010 0.006 0.009 75 0.026 0.020 0.021 0.022 70 0.021 0.024 0.027 0.024

88 0.011 0.010 0.006 0.009 90 0.027 0.021 0.022 0.023 85 0.022 0.025 0.028 0.025

102 0.012 0.011 0.007 0.010 104 0.028 0.022 0.023 0.024 99 0.023 0.026 0.029 0.026

119 0.012 0.011 0.007 0.010 118 0.029 0.023 0.024 0.025 113 0.024 0.027 0.030 0.027

134 0.012 0.011 0.007 0.010 132 0.030 0.023 0.024 0.026 127 0.025 0.028 0.031 0.028

148 0.012 0.011 0.007 0.010 146 0.032 0.025 0.026 0.028 142 0.026 0.029 0.032 0.029

164 0.012 0.011 0.007 0.010 164 0.033 0.026 0.027 0.029 159 0.027 0.030 0.033 0.030

179 0.013 0.012 0.008 0.011 178 0.035 0.027 0.028 0.030 174 0.028 0.031 0.034 0.031

198 0.013 0.012 0.008 0.011 192 0.036 0.028 0.029 0.031 194 0.028 0.032 0.036 0.032

215 0.014 0.013 0.009 0.012 227 0.036 0.028 0.029 0.031 222 0.029 0.033 0.037 0.033

230 0.014 0.013 0.009 0.012 257 0.037 0.029 0.030 0.032 252 0.030 0.034 0.038 0.034

245 0.015 0.013 0.010 0.013 280 0.037 0.029 0.030 0.032 280 0.031 0.034 0.038 0.034

266 0.015 0.013 0.010 0.013 300 0.037 0.030 0.031 0.033 300 0.031 0.035 0.038 0.035

300 0.016 0.014 0.011 0.013 --- --- --- --- --- --- --- --- --- ---

212

Table A.44: Concrete Expansion of Mix GUL


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0.000 0 0 0 0 0 0 0

22 0.008 0.007 0.006 0.007 21 0.007 0.012 0.008 0.009 20 0.012 0.014 0.010 0.012

36 0.009 0.008 0.007 0.008 35 0.012 0.017 0.013 0.014 34 0.016 0.018 0.013 0.016

52 0.010 0.009 0.008 0.009 51 0.015 0.022 0.017 0.018 52 0.02 0.023 0.017 0.020

79 0.009 0.008 0.007 0.008 78 0.019 0.026 0.021 0.022 77 0.025 0.028 0.022 0.025

111 0.011 0.010 0.009 0.010 110 0.021 0.028 0.023 0.024 109 0.028 0.032 0.025 0.028

146 0.013 0.012 0.011 0.012 145 0.023 0.030 0.025 0.026 144 0.029 0.033 0.026 0.029

174 0.014 0.013 0.012 0.013 173 0.024 0.031 0.026 0.027 172 0.030 0.034 0.027 0.030

204 0.016 0.015 0.014 0.015 203 0.025 0.034 0.028 0.029 202 0.030 0.035 0.028 0.031

233 0.016 0.015 0.014 0.015 232 0.025 0.034 0.028 0.029 231 0.032 0.037 0.030 0.033

280 0.017 0.016 0.015 0.016 250 0.026 0.036 0.030 0.031 280 0.033 0.038 0.031 0.034

300 0.017 0.016 0.015 0.016 270 0.027 0.036 0.030 0.031 300 0.033 0.038 0.031 0.034

--- --- --- --- --- 300 0.027 0.036 0.030 0.031 --- --- --- --- ---

213

Table A.45: Concrete Expansion of Mix HS


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0.000 0 0 0 0 0 0 0

22 0.008 0.012 0.010 0.01 21 0.006 0.006 0.009 0.007 20 0.006 0.005 0.004 0.005

37 0.011 0.015 0.013 0.013 38 0.009 0.009 0.012 0.010 37 0.011 0.01 0.009 0.010

79 0.013 0.018 0.015 0.015 78 0.009 0.010 0.014 0.011 77 0.016 0.014 0.012 0.014

111 0.015 0.021 0.018 0.018 110 0.010 0.011 0.015 0.012 109 0.017 0.015 0.013 0.015

146 0.016 0.022 0.019 0.019 145 0.011 0.012 0.016 0.013 144 0.018 0.016 0.014 0.016

174 0.016 0.022 0.019 0.019 173 0.012 0.013 0.017 0.014 172 0.02 0.018 0.016 0.018

204 0.016 0.022 0.019 0.019 203 0.013 0.014 0.018 0.015 202 0.02 0.018 0.016 0.018

233 0.017 0.023 0.020 0.020 232 0.013 0.014 0.018 0.015 231 0.021 0.019 0.017 0.019

276 0.017 0.024 0.021 0.021 275 0.015 0.015 0.020 0.017 274 0.022 0.021 0.019 0.021

300 0.018 0.024 0.021 0.021 300 0.015 0.015 0.020 0.017 300 0.023 0.021 0.019 0.021

214

Table A.46: Concrete Expansion of Mix HS-17µm


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

22 0.008 0.007 0.012 0.009 22 0.009 0.008 0.006 0.008 22 0.013 0.009 0.011 0.011

36 0.010 0.009 0.014 0.011 37 0.012 0.010 0.008 0.010 37 0.014 0.010 0.012 0.012

79 0.011 0.010 0.015 0.012 79 0.013 0.011 0.009 0.011 79 0.015 0.011 0.013 0.013

111 0.011 0.010 0.015 0.012 111 0.014 0.012 0.010 0.012 111 0.016 0.012 0.014 0.014

146 0.011 0.011 0.017 0.013 146 0.016 0.015 0.011 0.014 146 0.017 0.013 0.015 0.015

174 0.012 0.012 0.018 0.014 174 0.017 0.016 0.012 0.015 174 0.019 0.015 0.017 0.017

204 0.013 0.013 0.019 0.015 204 0.018 0.017 0.013 0.016 204 0.020 0.016 0.018 0.018

233 0.014 0.014 0.019 0.016 233 0.020 0.019 0.015 0.018 233 0.020 0.017 0.019 0.019

278 0.014 0.015 0.019 0.016 278 0.021 0.019 0.015 0.018 280 0.021 0.017 0.019 0.019

300 0.014 0.015 0.019 0.016 300 0.021 0.019 0.015 0.018 300 0.021 0.017 0.019 0.019

215

Table A.47: Concrete Expansion of Mix HS-3µm


55°C 70°C 82°C

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

Age

(Days) 1 2 3

Average

Expansion

(%)

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

22 0.012 0.011 0.007 0.010 21 0.008 0.008 0.011 0.009 20 0.010 0.010 0.013 0.011

38 0.014 0.013 0.009 0.012 36 0.010 0.010 0.013 0.011 36 0.011 0.011 0.014 0.012

79 0.014 0.013 0.009 0.012 78 0.010 0.010 0.013 0.011 77 0.013 0.013 0.016 0.014

111 0.015 0.014 0.013 0.014 110 0.010 0.010 0.013 0.011 109 0.014 0.014 0.018 0.015

146 0.015 0.014 0.009 0.013 145 0.011 0.011 0.014 0.012 144 0.014 0.015 0.019 0.016

174 0.017 0.016 0.012 0.015 173 0.013 0.013 0.016 0.014 172 0.015 0.016 0.020 0.017

204 0.019 0.018 0.012 0.016 203 0.014 0.015 0.019 0.016 202 0.017 0.018 0.022 0.019

233 0.020 0.019 0.013 0.017 232 0.014 0.015 0.019 0.016 231 0.018 0.019 0.023 0.020

276 0.02 0.019 0.015 0.018 275 0.016 0.017 0.021 0.018 274 0.019 0.020 0.024 0.021

300 0.021 0.019 0.014 0.018 300 0.016 0.017 0.021 0.018 300 0.020 0.020 0.023 0.021

216

A.7.6 Scanning Electron Microscopy

In this section, flatbed scanner images of thin-sections used in this thesis are presented

which shows the locations of SEM images. Furthermore, additional SEM images are

presented.

Figure A.11: Flatbed Scanner Image of Thin-Section Sowing Locations of SEM Images

of Mix GU-17µm-82°C

217



Fig. 5.17 a

Fig. A.17 a

Fig. A.17 b

218



Fig. 5.17 b

Fig. A.19 a

Fig. A.19 b

219


of Mix GU-70°C

Fig. 5.18a

Fig. A.18a

Fig. A.18b

220


of Mix GU-82°C

Fig. 5.18b

Fig. A.20

221


of Mix HS-17µm-82°C

Fig. 5.19

Fig. A.24

Fig. A.23

222

Figure A.17: SEM (Backscattered Electron) Images of Concrete Mixture GU-17µm-55°C

(a)

(b)

223

Figure A.18: SEM (Backscattered Electron) Images of Concrete Mixture GU-70°C

Showing Microcracks (Circles)

(a)

(b)

224


(a)

(b)

225

Figure A.20: SEM (Backscattered Electron) Images of Concrete Mixture GU-82°C

Showing Narrow Gaps Surrounding the Sand Particles, Ettringite Deposits in the

Interfacial Transition Zone (squares) and Microcracks (circles)

226

Figure A.21: SEM (Backscattered Electron) Images of Concrete (GU-17µm-82°C)

Showing Narrow Empty Gaps (Circles) Surrounding Sand Particles and Ettringite

Deposits (Squares) Found in the Interfacial Transition Zone

227


Showing Showing Narrow Empty Gaps Surrounding Sand Particles

228

Figure A.23: SEM (Backscattered Electron) Images of Concrete Mixture HS-17µm-82°C

Figure A.24: SEM (Backscattered Electron) Images of Concrete Mixture HS-17µm-82°C

229

Appendix B Publication Plan

The following are list of journal papers created from the results and findings of this thesis:

Paper I (based on Chapter 2)

Aqel, M., and Panesar, D. Physical and Chemical Effects of Limestone Filler on Steam

Cured Cement Paste, Mortar and Concrete. Submitted to Cement and Concrete Research

Journal on May 2015.

Paper II (presented in Chapter 3)

Aqel, M., and Panesar, D. (2016). Hydration Kinetics and Compressive Strength of Steam-

Cured Cement Pastes and Mortars Containing Limestone Filler. Construction and Building

Materials, Vol. 113, 359-368.

Paper III (presented in Chapter 4)

Aqel, M., Panesar, D., Rhead, D., and Schell, H. Effect of Cement and Limestone Particle

Size on the Durability of Steam Cured Self-Consolidating Concrete. Submitted to Cement

and Concrete Composites Journal on May 2016.

Paper IV (presented in Chapter 5)

Delayed Ettringite Formation in Self-Consolidating Concrete Containing Limestone Filler.

To be submitted on August 2016.

Documents

Steam Cured Self-Consolidating Concrete and the …...ii Steam Cured Self-Consolidating Concrete and the Effects of Limestone Filler Mohammad A. Aqel Doctor of Philosophy Civil Engineering