Influence of Aggregate Gradation & Mineral Admixture on ...xajzkjdx.cn/gallery/18-april2020.pdf · Influence of Aggregate Gradation & Mineral Admixture on Strength & Durability Properties

Influence of Aggregate Gradation & Mineral Admixture on Strength &

Durability Properties of Self Compacting Concrete

Ahmed Abdul Ahad*, Adapala Sunny Suprakash**, Md Muheeb Ahmed*, ©M.S. Haji Sheik Mohammed***

* Research Scholar, **PG Student, *** Professor,

Department of Civil Engineering, B.S. Abdur Rahman Crescent Institute of Science and

Technology, Chennai 600048, India

Abstract

The scope of present investigation is to develop a Self-Compacting Concrete and to conduct fresh, mechanical and

durability properties by replacing 30% cement with class F fly ash and comparing with conventional concrete. Variables

involved in the study are water powder ratio, fine aggregate and coarse aggregate with combination of 20mm downgraded

and 12mm downgraded. Sieve analysis was carried out for better particle size distribution and to have suitable packing void

content. To optimize perfect mix totally seven mixes were carried out with different w/p ratio, different proportions of fine

and coarse aggregate. Finally mix M7 satisfies the fresh properties as per EN12350 specifications & guidelines. Mechanical

and durability properties of developed SCC & conventional concrete were conducted. Mix M7 shows appreciable increase

in compressive strength, split tensile strength and modulus of elasticity of order 35%, 26.63% and 52.38%. Furthermore,

SCC performs much better in case of ACT, chloride penetration and water absorption when compared to conventional

concrete. The developed SCC can be employed for special applications such as bridges, pre-fabricated structures, deck

slabs which are heavily congested with steel rebars. Also, another mix M6 which does not satisfy EN12350 ranges but can

be used for the application of pre-fabricated wall panels and conventional construction purpose. Cost analysis also favours

SCC by reduction of about 11.67% over conventional concrete.

Key words: Self-compacting concrete; conventional concrete; fly ash; fresh properties; mechanical and durability

properties; cost analysis.

1. INTRODUCTION

Concrete is considered as one of the most popularly used man-made construction material due to the possibility of use of

locally available raw materials. Concrete with time becomes hard like stone, due to the chemical reaction between cement

and water, known as hydration of cement and its continuous process makes concrete harder gradually. Concrete is strong in

compression but weak in tension, so it requires additional material to enhance its tensile property. However, steel is strong in

tension, so the steel is reinforced with concrete in combination, the problem which arising out of tensile weakness of concrete

can be overcome. The special requirements of modern concrete like good workability, higher strength and better durability

can be achieved by incorporating several chemical and mineral admixtures. The emission of carbon dioxide, the greenhouse

gas, from cement manufacturing industry can be reduced through the blending of various cement replacement materials. Self-

compacting concrete (SCC) is an innovative concrete that does not require vibration for placing and compaction. It is able to

flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested

reinforcement. The hardened concrete is dense, homogeneous and has the same engineering properties and durability as

conventionally vibrated concrete.

Journal of Xi'an University of Architecture & Technology

Volume XII, Issue IV, 2020

Issn No : 1006-7930

Page No: 208

Canadian researchers have determined that CO2 emission reductions can be accomplished by substituting high volumes of

fly ash as a replacement for cement. Aiqin Wang et al (1). A simple mix design method for self-compacting concrete in

which the amount of aggregates required was initially determined and the paste of binders was then filled into the voids.

Nan Su et al. (2). An economical SCC can be developed by the replacement of cement with fly ash by maintaining the

powder content at 400 kg/m3 was studied by Bouzoubaa et al. (3). Bertil Persson (4) carried out an experimental and

numerical study on eight mix proportions of sealed or air-cured specimens with water binder ratio (w/b) varying between

0.24 and 0.80. Hajime Okamura et al. (5) done investigations for establishing a rational mix design method and self-

compactability testing methods have been carried out from the viewpoint of making Self-compacting concrete as Standard

Concrete. Nicolas et al. (6) conducted a comprehensive experimental program and statistical analysis to evaluate the

repeatability, responsiveness and relative cost of commonly used SCC workability test methods. Sleymani Ashtiani et al.

(7) studied a comparable concrete compressive strength for two different concretes. It was found that with an equivalent w/b

ratio, HSSCC develops considerably higher compressive strength (more than 15 MPa) compared to that of CVHSC.

Dhiyaneshwaran et al. (8) conducted a study on durability characteristics of self-compacting concrete using different

percentages of fly ash. Replacement of 30% flyash shows comprehensive results in flowability, mechanical & durability

properties. Seddik et al. (9) studied the mechanical properties of SCC made with local materials such as limestone powder,

silica fume and blast furnace slag have been used as adjuvant in self-compacting concrete and concluded that silica fume,

have shown an improvement in compressive and tensile strengths. Pai et al. (10) conducted a performance analysis of fresh

concrete properties and mechanical properties of both GGBS and SF based SCC mixes, and mainly concentrates to achieve

SCC of M25 grade by the method proposed by (1). Olafusi et al. (11) conducted a comparison of rheological properties and

compressive strengths of self-compacting concrete (SCC) and conventional cement concrete. N. Mohammed Rayyan et al.

(12) developed three different SCC mixes by the incorporation of fly ash and metakaolin and concluded that high usage of

metakaolin increases the hardened and durability properties of SCC. However, the workability properties doesn’t satisfies

the EFNARC guidelines.

SCC is a major tool for the emerging construction technology which has become a hot area for research. The increased cost

of labour and wear and tear of equipment’s attracts the contractors, engineers, owners and producers to use SCC for safe and

rapid construction. Many researchers have focused on fresh and hardened properties by the incorporation of mineral

admixtures like fly ash, GGBS and silica fume at different dosage of super plasticizers. However, the results showed that the

mineral admixtures enhance the rheological & mechanical properties of SCC extensively. Furthermore, these mineral

admixtures are also added as a filler material to enhance the rheological properties. There is a need of study to know the

effect of aggregate size which basically allows the concrete to settle under its own weight and developing an economical

concrete by the replacement of cement with fly ash. Since fly ash is a by-product from thermal power stations which is

universally accepted as a supplementary cementitious material and reduces the emission of CO2.

This study majorly focused on the effect of size of aggregate and constant percentage of fly ash and super plasticizer and its

effect on rheological, mechanical & durability properties of SCC. After several trials, a SCC has been developed which

satisfies all the recommendations of EFNARC. Furthermore, mechanical and durability properties of SCC have been

compared with conventional concrete



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2. MATERIALS & MIX DESIGN

Ordinary Portland cement of 53 grade conforming to IS 12269:1987 (Concrete mix proportioning – Guidelines) was used.

Locally available natural river sand was used as fine aggregate. The property of sand is determined by conducting tests as per

IS: 2386 (part 1). The results obtained from the sieve analysis indicate that the sand conforms to zone II of IS: 383-1970. For

the development of self-compacting concrete, 20mm and 12mm downgraded coarse aggregates with different proportions

were used for this study. Since, the shape and particle size distribution is very important for packing void content, water

absorption and grading in order to produce good quality SCC. Figure 1 shows the particle size distribution of coarse

aggregate.

Figure 1: shows particle size distribution of coarse aggregate

Flyash

Flyash pulverized fuel ash which is also known as fly ash is also used as a filler material in proposed SCC. It was collected

from Ennore Thermal Power Plant. Table 1 & 2 shows the physical properties & chemical composition of fly ash

respectively.

Table 1: Physical properties of fly ash

S. No. Properties Results obtained

1. Type fly ash Class F

2. Specific gravity 1.745

Table 2: Details of chemical composition of fly ash

Sl. No. Chemical composition*

Result

obtained

1. Calcium Oxide, CaO (% by mass) 1.7

2. Silicon dioxide, SiO (% by mass) 62.5



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3. Aluminum Oxide, Al2O3 (% by mass) 26.5

4. Ferric oxide, Fe2O3 (% by mass) 4.2

5. Magnesium Oxide, MgO (% by mass) 0.8

6. Sulphur trioxide, SO3 (% by mass) 0.2

7. Sodium oxide, Na2O3 (% by mass) 0.12

8. Potassium oxide, K2O (% by mass) 1.14

9. Loss in ignition 1.0

*Source acquired from the manufacturer

Super-plasticizer

Master Glenium Sky 8233(Formerly Glenium B233), high performance super-plasticizer, poly-carboxylic ether based,

Master Builders solutions, BASF India Ltd. is used. The physical and chemical properties of super-plasticizer were acquired

from manufacturer and are shown in Table 3.

Table 3: Physical and Chemical Properties of Super-plasticizer

Properties Results

Colour aspect Light brown liquid

Specific gravity 1.08 ± 0.01 @ 25°C

PH ≥6

Chloride ion content <0.2%

Mix proportions for conventional concrete

Table 4 shows the mix proportions for conventional concrete which has been designed as per IS 456 : 2000 by replacing

cement with flyash of order 30% by weight of cement.

Table 4: Mix Proportion for conventional concrete

Sl. No. Materials Proportions

(Kg/m3)

1. OPC 53 Grade Cement 280

2. Fly ash (30%replacement of cement) 120

3. Water content 180

4. Fine Aggregate 729.60

5. Coarse Aggregate [60%(20mm downgraded) – 40%(12mm

downgraded)] 1053.85



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Mix design methodology for Self-Compacting Concrete (SCC)

The Self-compacting concrete mix composition should satisfy the all performance criteria for the concrete in both

characteristic properties like filling ability, passing ability and segregation resistance of the concrete and hardened state

properties as per EN 206 shall be fulfilled.

Adjustments to the mix proportion

Laboratory trials were conducted to verify the initial mix composition properties. In addition, certain adjustments to the mix

composition should be made when required. Once all requirements are met with, the designed mix should be tested at the

concrete plant or at site. This is carried out for a full-scale process.

In the event of unsatisfactory performance of the designed mix, then fundamental redesign of the mix should be considered.

Figure 2 shows the layout of design methodology for self-compacting concrete. Based on the problem incurred, the following

courses of action might be appropriate:

● Usage of additional or different types of filler, (if available)

● Proportion modification for sand or coarse aggregate

● Adjustments in dosage of viscosity modifying agent

● Adjusting the dosage of the super-plasticizer or any other viscosity modifying agent

● Usage of various types of super-plasticizer (and/or VMA), more compatible with local materials

● Adjustment of admixture dosage in order to modify the water content, and hence the water/powder ratio.

Figure 2: Layout of design methodology for self-compacting concrete

Marsh cone Test

This test is carried out as per EN 445, and the main objective of this test is to determine the super-plasticizer dosage for the

optimised paste. Figure 3 shows the behaviour of flow time as the function of dosage of super plasticizer



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Figure 3: Flow time as a function of super-plasticizer dosage.

Mix proportions and Fresh Concrete properties of SCC

Table 5 shows the mix proportions for seven mix proportions out of which mix M6 and M7 satisfies the conditions for

EFNARC.

Table 5: Different proportions for developed concrete

Proportions M1 (60-

40)

M2 (60-

40)

M3 (50-

50)

M4 (40-

60)

M5 (20-

80)

M6 (20-

80)

M7 (20-

80)

As per EN 12350

OPC 53 Grade

cement (kg/m3)

280 280 280 294 280 294 308

Fine content about 400-

600kg/m³

Flyash 30%

replacement of

cement (kg/m3)

120 120 120 126 120 126 132

Water content

(kg/m3)

156 156 156 163.8 156 163.8 171.6 150 – 210 kg/m3

SP dosage (%) 1 1 1 1 1 1 1 sp/b=1.1

Sand (kg/m3) 734 710 705.4 695.4 723.3 723.3 716.3 Gravel /sand ratio of



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Gravel (kg/m3) 782 788 748.6 748.6 640.7 640.7 640.7

about 1

Table 6: shows the fresh properties of trial mixes

Mix Name

Type of Test

M1 (60-

40)

M2

(60-40)

M3 (50-

50)

M4 (40-

60)

M5 (20-

80)

M6 (20-

80)

M7

(20-80)

As per EN

12350

T50cmSlump Flow (Sec) - - 5 - 5 4 3 ≤5

Slump Flow Final

Spread (mm)

- - 610 - 618 640 668 >600

V – Funnel (sec) 64 58 48 38 41 15 11 ≤12

U – Box Text (mm) - - - - - 50 0 ≤ 30

L – Box Test - - - - - 0.2 0.8 > 0.80

Slump flow test is carried out for 4 different mixes as per EN 12350-2, the final spread diameter of concrete and time taken

for 500mm diameter spread is noted. Mix M3 and mix M5 shows same T50 readings whereas the final spread varies

marginally. This is due to decrease in the size of aggregate which clearly states that aggregate plays a crucial role in flow

ability of SCC. Mix M6 has less slump flow when compared to Mix M7 and also it has been found that slump flow increases

with increase in paste volume and fine content. Thus, mix M7 has better flow characteristic than mix M6. This determine that

mix M7 has better filling ability. Figure 4 shows the relation of slump flow & V-funnel time with fine content.



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Figure 4: Relation of slump flow & V-funnel with fine content.

V – funnel test is carried out for the two mixes M6 & M7 and the result obtained is listed in the Table 6. Mix 6 & mix 7 has

same aggregate ratio of 20% of 20 mm downgraded and 80% of 12 mm downgraded gravels but the minor change of paste

content increases the flow time for mix M7 thereby satisfying the acceptance criteria for EN 12350.

L-Box, U-Box Test was also carried out for the two mixes mix M6 & M7. In this test mix M7 satisfies the favourable

conditions of European standards. Therefore, an economical mix of SCC for domestic and commercial projects has been

developed with the replacement of cement with fly ash and aggregate gradation. Since mix M7 satisfies all the

specifications of EN 12350, detailed mechanical & durability properties of mix M7 and conventionally designed concrete

has been compared.

3. EXPERIMENTAL INVESTIGATION

Various tests were conducted to determine the mechanical and durability performance of both conventional concrete and

self-compacting concrete. These tests were carried out as per Bureau of Indian standard (BIS) / American standard for

testing materials (ASTM) / guidelines prescribed by premier research organizations. Strength related tests such as

Compressive strength test, Split-tensile strength test, Modulus of elasticity and Durability related studies such as

Accelerated corrosion test, Chloride penetration test, Water absorption test.

Compressive strength test

The compressive strength of concrete specimens was evaluated by conducting compressive strength test as per BIS 456:2000

Method of test - Compression strength of concrete. This test is carried out in 3000 KN capacity of digital compressive

testing machine. Concrete cubes of size 100mm x 100mm x 100 mm were casted with conventional concrete and self-

compacting concrete.Test has been conducted with 3 cubes of two mixes and reported the average value at different ages i.e.

7 days, 14 days, 28 days and 56 days compressive strength.

Split tensile strength test

The split tensile specimen strength of the specimen is determined by conducting split strength test as per ASTM C496

Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens. The split tensile strength test



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was carried out in 150 tonnes capacity compression testing machine. Concrete cylinders of size 150mm diameter and 300mm

height were casted with conventional concrete and SCC. Test has been conducted with 6 cylinders of two mixes with their

respective age of 28days.

Modulus of elasticity

This test is carried out as per BIS 5816:1999 Determination of the Modulus of Elasticity by means of an extensometer.

The modulus of elasticity test was carried out in 150 tonnes capacity compression testing machine. Concrete cylinder sizes of

150mm diameter and 300mm height were casted with conventional concrete and Self-compacting concrete. Totally six tests

were conducted on two concrete mixes at the age of 28days.

Accelerated corrosion test

The Accelerated corrosion test is a crash test carried out to determine the durability parameters of rebars or concrete. This test

was conducted as per guidelines given by (CSIR-SERC) Structural Engineering Research Institute and (CECRI)

Central Electro Chemical Research Institute. It is based on basic principles that rebar starts corrode in favourable

condition to get increase in its volume. Once the volume increases in concrete rebar, the tensile stresses developed in the

concrete rebar then cracks were develope perpendicular to change its volume in rebar. The specimens were in the form of

concrete cylinder centrally embodied with 12mm rebar used and specimen sizes 70mm diameter and 115mm height.

Chloride penetration test

Chloride penetration test is conducted to know the resistance of concrete towards penetration of chloride ions without any

other external inducing agent. The specimen were in the form of concrete cube sizes 100mm x 100mmx 100mm and totally

6 specimens of two mixes were investigated for chloride penetration test which was cured in water for 28 days prior to

immersion in chloride solution.

Water absorption test

The pore structure of the concrete has great importance in the case of durability of material. The characterization of this

structure of pore of a simple test is investigated, in order to find simple compliance criterion with respect to concrete

durability. This test is conducted with concrete cube specimens of size 100mm x 100mmx 100mm of two mixes with total of

6 specimens. This water absorption test is carried out after 28 days of curing.

4. RESULTS & DISCUSSIONS

Mechanical Properties

Figure 5 shows the comparison of compressive strength for control and self-compacting concrete at different ages. It can be

seen that there is a similar compressive value for control and SCC at the tested age of 7day and 14 day. Whereas 28 day

compressive strength values exhibit an significant increase in compressive strength for self compacting concrete of the order

of 34% as compared to conventional concrete. Appreciable increase in compressive strength of the order of 11% was

observed for SCC when tested at the age of 56 days as compared to conventional concrete. It can be concluded that self



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compacting concrete offers significantly improved compressive strength at the age of 28 days as compared to control

concrete.

Figure 5: shows the compressive strength of conventional & mix M7

Figure 6 shows the observation of split tensile strength of conventional concrete and SCC M7. The split tensile strength

obtain for conventional concrete is 2.28MPa which is less than the 2.8 MPa (average value suggested by ASTM C496) for

150mm diameter and 300mm height cylinder specimen. The split tensile strength obtain for SCC mix is 2.91 MPa which is

more than the target average strength of the specimen size. From this result it can be inferred that SCC mix offers excellent

improvement in split tensile strength of the order of 28% as compared to conventional concrete.

Figure 6: Split tensile strength of conventional & mix M7

Modulus of elasticity

The SCC mix has a modulus of elasticity value of 32GPa and for conventional concrete is 21 GPa. The SCC mix M7 shows

52.38% increase in modulus of elasticity value as compared to control concrete. Figure 7 shows the stress – strain behaviour

of conventional and SCC.



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Figure 7: Stress -strain behaviour of Conventional and SCC mix

Durability Properties

Figure 8 shows the time to cracking of control and SCC specimen in the accelerated corrosion test. In the case of SCC mix,

the time taken for the appearance of first crack is at 143 hours due to corrosion of rebar, and initial corrosion started at 95

hours of test period. Whereas, in conventional concrete, the time taken for the appearance of crack is at 175 hours and initial

corrosion starts at 144 hours. SCC mix has taken 32 hours earlier for the appearance of crack when compared to

conventional concrete mix which needs further study.

It can be found that SCC mix shows 18.28% decrease in corrosion resistance when compared to conventional concrete. This

may be due to the fact that in case of SCC specimen, corrosion initiates from the bottom surface of the specimen due to lack

of cover concrete at the bottom surface because high flowability of SCC. Further care in preparation of specimen may lead

to improved crack resistance for SCC specimens when exposed to highly accelerated conditions. Figure 9 shows the view of

corroded specimen after accelerated corrosion test.

Figure 8: Accelerated corrosion test for conventional & SCC mix M7



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Figure 9: View of corroded specimen after accelerated corrosion test.

The average chloride penetration depth observed for control and self-compacting concrete specimens are 3.25mm and

2.5mm respectively. It can be concluded that self-compacting concrete significantly reduces the chloride penetration of the

order of 23% as compared to conventional concrete. This may be due to the dense packing of concrete micro structure

which averted the penetration of chloride ions inside the SCC.

Figure 10 shows the water absorption behaviour of conventional concrete and SCC. It can be observed that control concrete

exhibits increased water absorption from the initial immersion period and that trend continued until the 24 hour test period.

Whereas for SCC there is a 50% reduction in water absorption was observed from the initial immersion period. Afterwards

also the increase in water absorption is minimal and attained a water absorption (%) of 1.02 at the end of 24 hour.

Figure 10: Water absorption behaviour of control concrete and SCC

Figure 11 shows the comparison of water absorption for control and SCC. It reveals that SCC exhibits excellent water

impermeability characteristics as compared to control concrete since there is a significant reduction in water absorption in

all the tested times through the test period. There is a significant reduction in 24 hour water absorption for self-compacting

concrete of the order of 51% as compared to control concrete.



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Figure 11: Comparison of % water absorption for Control and SCC at the end of 24 hours

Typical Mix Composition Comparison between Conventional Concrete and SCC

In Self-compacting concrete mix designing it is most useful to consider the relative proportions of key components by

volume rather than by mass. The main differences between conventional concrete and SCC are related to the behaviour in the

fresh state. Table 7 shows the mix composition of materials percentage in both conventional concrete and SCC in terms of

volume. When compared to conventional concrete the percentage of materials is different in total volume of SCC. As per

EFNARC Specification and Guidelines for Self-Compacting Concrete the volume of paste should be 34% to 40% of total

volume of concrete, coarse aggregate normally ranges 28% to 35% by whole volume and the fine aggregate content balances

the volume of the other constituents and it ranges volume of 34% to 40% of the mortar volume. So in the present study the

volume of all the materials of the developed mix composition of SCC satisfies the as per the EFNARC guidelines. The paste

volume of the developed SCC is 40.37%, coarse aggregate 26% of its total volume of concrete and fine aggregate is 44% of

its total volume of mortar.

Table 7: Comparison of mix composition between conventional concrete and Self-compacting concrete

Materials

Mix composition in volume (%)

Conventional

concrete (%)

Self-compacting

Concrete (%)

Cement 9.27 11.8

Fly ash 6.87 8.79

Paste 34.15 40.37

Water 18.01 19.91

Super-plasticizer - 0.46

Sand 28.97 32.98

Sand (in mortar) 45.88 44.58

Gravel 36.86 26



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Comparison of Cost analysis between Conventional Concrete and SCC

Table 8 and 9 shows the cost analysis of conventional concrete and Self-compacting concrete for 1m3 with the both

developed mix proportions of the present study. It can be observed that manufacturing cost for conventional concrete is Rs.

9,658/- and for SCC is Rs. 8,531/-. This indicates that self compacting concrete costs 12% less than the conventional

concrete. The cost escalation in conventional concrete may be due to usage of more labour force, equipment for vibrating

etc. But considering the materials cost alone SCC cost 21.49% more than the conventional control concrete due to

incorporation of mineral admixtures, chemical admixtures (Super-plasticizer). But considering machinery and labour, there

is a cost reduction up to 46.31% was observed for SCC as compared to conventional concrete.

Table 8: Cost analysis for Conventional Concrete for 1m3

Material Qty. Units Standard

Unit

Material Cost

(Rs.)

Total Cost

(Rs.)

Cement 280 kg/cu.m 50kg 385 2156

Fly ash 120 kg/cu.m 1kg 2.5 300

Sand 729.6 kg/cu.m 1cu.ft 80 1145.81

Gravel 1053.5 kg/cu.m 1cu.ft 40 823.44

Total 4425.25

Machinery Units Rent/hr (Rs.) Total Cost

(Rs.)

Mechanical mixer 1 125 125

Mechanical vibrator 1 62.5 62.5

Total 187.5

Labour Units Cost / day Total Cost

(Rs.)

Mason 3 650 1950

Labour 1 500 500

mixer operator 1 1000 1000

vibrator operator 1 600 600

Total 4050

Total of materials, machinery and labour 8662.75

Add 1 ½ % Water charges 130

Add 10% Contractor’s profit 866

Grand Total 9658.75



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Table 9: Cost analysis for SCC for 1m3

Material Qty. Units Standard Unit Material Cost

(Rs.)

Total Cost (Rs.)

Cement 308 kg/cu.m 50kg 385 2371.6

Fly ash 132 kg/cu.m 1kg 2.5 330

Sand 716.3 kg/cu.m 1cu.ft 80 1146.08

Gravel 640.7 kg/cu.m 1cu.ft 40 500.74

Super-plasticizer 5.14 Lit 1lit 200 1028

Total 5376.42

Machinery Units Rent/hr (Rs.) Total Cost (Rs.)

Mechanical mixer 1 125 125

Total 125

Labour Units Cost / day Total Cost (Rs.)

Mason 1 650 650

Labour 1 500 500

mixer operator 1 1000 1000

vibrator operater Nil Nil Nil

Total 2150

Total of materials, machinery and labour 7651.42

Add 1 ½ % Water charges 115

Add 10% Contractor’s profit 765

Grand Total 8531



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5. CONCLUSIONS

Based on experimental test results obtained the following conclusions are drawn.

● The mix M7 design has achieved an appreciable performance against segregation, filling ability and passing ability of

fresh concrete. The other 6 mixes are found with less volume of paste and more gravel, resulting in less workable

properties when compared to mix M7 whose paste volume is more and less gravel volume. It is inferred that increase of

paste volume, increases the workability properties of SCC mix.

● The final mix of SCC results obtained in the fresh concrete properties satisfies all the ranging values in the

specifications and guidelines of EFNARC. It can be concluded that SCC M7 can be used for congested reinforcement

areas, bridges, deck slabs, prefabricated structures and also for other special applications in modern construction

technology.

● The results obtained for SCC mix M6 doesn’t satisfies fresh properties like L-box and U-box ranging values in the

specifications. Therefore, this concrete mix cannot used for congested reinforced structures and can be preferably used

for prefabricated wall panels for filling in rapid wall technology.

● Compressive strength of conventional concrete has appreciably achieved its target mean strength of 43.25 MPa in 28

days and developed self-compacting concrete has achieved mean strength 58.6 MPa even though it contains more paste

content.

● Split tensile strength of conventional concrete is 18.57% less than the average tensile strength as per ASTM C496.

Whereas the split tensile strength of SCC is 3.92% more than the average tensile strength and 27.63% more than the

conventional concrete tensile strength.

● Modulus of elasticity of SCC is 52.38% more than conventional concrete due to its high paste content.

● In case of accelerated corrosion test, SCC mix shows 18.28% decrease in corrosion resistance when compared to

control concrete, as the corrosion initiates from the bottom of the specimen due to lack of cover concrete at the bottom

surface because high flowability of SCC.

● In water absorption test the SCC mix shows good durability performance than conventional concrete. This is due to

high packing density of the concrete. There is a significant reduction in 24 hour water absorption for self compacting

concrete of the order of 51% as compared to control concrete.

● Chloride permeability of the self-compacting concrete and conventional concrete is low as observed from the chloride

penetration test. Self compacting concrete significantly reduces the chloride penetration of the order of 23% as

compared to conventional control concrete.

● Cost analysis reveals that SCC offers 11.67% reduction in total production cost when compared to conventional

concrete and also enhancing strength and durability properties.

● It can be concluded that the self-compacting concrete exhibits high performance in terms of excellent workability

which results in enhanced strength and durability properties in addition to cost benefits and recommended for use in

concreting with special applications.



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