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8/10/2019 STUDIES ON REACTIVE POWDER CONCRETE.docx
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STUDIES ON REACTIVE POWDER CONCRETE-ULTRA
HIGH STRENGTH CONCRETE
SEMINAR REPORT
Submi tted by
N. SIVA RAM KRISHNA
ROLL NO: 141519
in the partial ful fi llment of the requirements for
The award of the degree of
MASTER OF TECHNOLOGY
INENGINEERING STRUCTURES
Under The Guidance of
Dr.D.Ravi Prasad
Assistant Professor in Civil Engineering Department
NATIONAL INSTITUTE OF TECHNOLOGY
WARANGAL-506004
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NATIONAL INSTITUTE OF TECHNOLOGY
WARANGAL-506004
CERTIFICATE
This is certified thatN. SIVA RAMA KRISHNAhas submitted the seminar report on
STUDIES ON REACTIVE POWDER CONCRETE- ULTRA HIGH STRENGTH
CONCRETEin partial fulfillment of the 1stsemester M.Tech course in Engineering
Structures as prescribed by the National Institute of Technology, Warangal during
academic year 2014-2015 under the guidance of Dr .D.Ravi Prasad.
Dr.D.Ravi Prasad
Assistant Professor
Department of Civil Engineering
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ACKNOWLEDGEMENTS
I express my deep sense of gratitude to Dr.D.Ravi Prasad sir, Assistant Professor in
Department of Civil Engineering, National Institute of Technology, Warangal for his invaluable
guidance, motivation and constant encouragement throughout the course of this seminar work.
I will remain thankful to all the faculty members of Department of Civil Engineering,
NIT Warangal for their support during the course of this work.
Finally, we express gratitude to our parents for supporting us in every walk of life.
N. Siva Rama Krishna
M.Tech (Engineering Structures)
National Institute of Technology, Warangal
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ABSTRACT
Concrete is a versatile and critical material for the construction of infrastructure facilities throughout
the world. A new developing material known as reactive powder (RPC) is available that differs
significantly from traditional concretes. It is catching more attention nowadays because of its high
mechanical and durability characteristics. RPC mainly comprise of cement, silica fume, silica sand,
quartz powder and steel fibers. RPC has been able to produce with compressive strength ranging from
200 MPa to 800 MPa with flexural strength up to 50 MPa. There is no coarse aggregate is present in
RPC. Since coarse aggregate is the weak link the concrete. The production of very high strength normal
weight Reactive powder concrete (RPC) requires detailed investigation of number of factors that have
and what can be done to optimized their contribution to the attainment of very high compressive
strength. In the present seminar I will focus to study the effects of w/c ratio, amount of silica fume,
curing conditions and the effect of mineral, chemical admixtures to achieve compressive strength.
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CONTENTS
1. INTRODUCTION
2. LITERATURE REVIEW
3. COMPOSITION OF REACTIVE POWDER CONCRETE
4. BENEFITS AND LIMITATIONS OF RPC
5. EXPERIMENTAL PROCEDURE
6.
RESULTS & DISCUSSIONS
7. CONCLUSIONS
8. REFERENCES
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INTRODUCTION
RPC is ultra-high-strength and high ductility cementations composite with advanced mechanical and
physical properties. It is a special concrete where the microstructure is optimized by precise gradation
of all particles in the mix to yield maximum density. It doesnt contain coarse aggregate, but contains
cement, silica fume, sand, quartz powder and steel fiber with very low water binder ratio. The absence
of coarse aggregate was considered by inventors to be key aspect for the microstructure and
performance of RPC in order to reduce the heterogeneity between cement matrix and aggregate.
RPC with trade name DUCTAL was developed in France by researchers Mr.
Richard and Mr. Cheyrezy in the early 1990s at Bouygues, laboratory in France. The worlds first RPC
structure, the Sherbrooke Bridge in Canada, was constructed in July 1997. RPC has been able to
produce with compressive strength ranging from 200 MPa to 800 MPa with flexural strength up to 50
MPa. Although suitable guidelines are not available to produce RPC in India, the present study focuses
on developing RPC of compressive strength up to 150 MPa. Without using steel fibers we can produce
strength up to 200 MPa.
This new material demonstrates greatly improved strength and durability
characteristics compared with traditional or even high-performance concrete. Classified as Ultra-High
Performance Concrete (UHPC), or Reactive Powder Concrete (RPC). The improved properties of RPC
are obtained by improving the homogeneity of the concrete by eliminating large aggregates, increasing
compactness of the mixtures by optimizing packing density of fine particles, and using fine steel fibersto provide ductility.
RPC will be suitable for pre-stressed application and for structures acquiring light and
thin components such as roofs of stadiums, long span bridges, space structures, high pressure pipes, and
blast resistance structures and the isolation and containment of nuclear wastes.
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LITERATURE REVIEW
Many researchers have carried out studies on RPC in the past years to assess the properties and its
behavior. Some of the works carried out re discussed below:
Richard and Cheyrezy (1995) developed an ultra-high strength ductile concrete with the basic
principles of enhancing the homogeneity by eliminating the coarse aggregate and enhancing the
microstructure by post-set heat treatment. In addition, the ductility and tensile strength of concrete is
increased by incorporating small, straight, high tensile micro fibers. Two types of concretes are
developed and designated as RPC 200 and RPC 800. These concretes had exceptional mechanical
properties, which resulted in elimination of reinforcement, and reduction of materials resulting in
reduction of self-weight resulting in cost savings. The concrete finds its applications in industrial and
nuclear waste storage silos.
Chan and Chu, [2002] has studied the effect of silica fume on the bond characteristics of steel fiber in
matrix of reactive powder concrete (RPC) by bond strength, pullout energy, etc. Various silica fume
contents ranging from 0% to 40% are used in the mix proportions. Results of them show that the
incorporation of silica fume can effectively enhance the fibermatrix interfacial properties, especially in
fiber pullout energy.
Dili and Manu Santhanam (2005) developed two RPC mixes of 200MPa and 800MPa strength,
which could be suitable for nuclear waste containment structures. The workability and durabilityproperties were studied for the designed RPC mix. Also characterization of mechanical properties was
carried out. The durability test carried out for the RPC mixes showed that the flow table test was in the
range of 120%-140% and the water and chloride ion Permeability is extremely low. These test results
indicates the suitability of the designed RPC mix for nuclear waste containment structures.
S. Lavanya Prabha [2010] conducted a study on complete stress-strain curves from uniaxial
compression tests. The effect of material composition on the stress strain behavior and the toughness
index were studied. The highest cylinder compressive strength of 171.3 MPa and elastic modulus of
44.8 GPa were recorded for 2% 13 mm length fibers. The optimum fiber content was found to be 3% of
6mm length or 2% of 13mm length fibres. A new measure of compression toughness known as MTI
(modified toughness index) was proposed by them and it is found to range from 2.64 to 4.65 for RPC
mixes.
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COMPOSITION OF REACTIVE POWDER CONCRETE
RPC is composed of very fine powders (cement, sand, quartz powder, steel aggregates and silica fume),
steel fibres (optimal) and a super plasticizer. The super plasticizers, used at its optimal dosage, decrease
the water to cement ratio (w/c) while improving the workability of the concrete. A very dense matrix is
achieved by optimizing the granular packing of the dry fine powders. This compactness gives RPC,
ultra-high strength and durability. Reactive powder concretes have compressive strengths ranging from
200 MPa to 800 MPa.
Mr. Richard and Mr. Cheyrezy indicate the following principles for developing RPC.
1. Enhancement of homogeneity by elimination of coarser aggregates.
2. Enhancement of compacted density by optimization of the granular mixture.
3. Enhancement of the microstructure by Post-set heat-treatment
4. Enhancement of ductility by addition of small-sized steel fibres
5. Application of pressure before and during setting to improve compaction
6. Utilization of the pozzolonic properties of silica fume.
7. The optimal usage of super plasticizer to reduce w/c and improve workability.
Table 1 lists salient properties of RPC, along with suggestions on how to achieve them. Table 2
describes the different ingredients of RPC and their selection parameters. The tables are obtained from
literature. The mixture design of RPC primarily involves the creation of a dense granular skeleton.Optimization of the granular mixture can be achieved either by the use of packing modelsor by particle
size distribution software, such as LISA[developed by Elkem ASA Materials].
Table: 1 Properties of RPC enhancing its homogeneity and strength
Property of
RPC
Description Recommended Values Types of failure
eliminated
Reduction in
aggregate size
Coarse aggregates are
replaced by fine sand,
with a reduction in the
size of the coarsest
aggregate by a factor of
about 50.
Maximum size of fine
sand is 600 m
Mechanical,
Chemical &
Thermo-mechanical
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Enhanced mechanical
properties
Improved mechanical
properties of the paste
by the addition of silica
fume
Youngs modulus
values in 50 GPa75
GPa range
Disturbance of the
mechanical stress field.
Reduction in aggregate
to matrix ratio
Limitation of sand
content
Volume of the paste is
at least 20% greater
than the voids index of
non-compacted sand.
By any external source
(e.g., formwork).
Table 2: Selection Parameters for RPC components
Components Selection
parameters
Function Particle Size Types
Sand Readily available
and low cost.
Good hardness
Give strength,
Aggregate
150 m
to
600 m
Natural,
Crushed
Cement C3S: 60%;
C2S : 22%;C3A : 3.8%;
C4AF: 7.4%.
(optimum)
Binding material,
Production ofprimary hydrates
1 mto
100 m
OPC,Medium
fineness
Quartz Powder
fineness
Max. reactivity
during heat-
treating
5 m
to
25 m
Crystalline
Silica fume Very less quantity
of impurities
Filling the voids,
Enhance
rheology,
Production of
secondary
hydrates
0.1 m
to
1 m
Procured from
ferrosilicon
industry
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Steel fibers Good aspect ratio Improve ductility L : 1325 mm
: 0.150.2 mm
Straight
Super Plasticizer Less retarding
characteristic
Reduced W/C - Polyacrylate
based
BENEFITS AND LIMITATIONS OF RPC
Benefits of RPC:
i. RPC is a better alternative to High Performance Concrete and has the potential to structurally
compete with steel.
ii. Its superior strength combined with higher shear capacity results insignificant dead load
reduction and limitless structural member shape.
iii. With its ductile tension failure mechanism, RPC can be used to resist all but direct primary
tensile stresses. This eliminates the need for supplemental shear and other auxiliary reinforcing
steel.
iv. RPC provides improve seismic performance by reducing inertia loads with lighter members,
allowing larger deflections with reduced cross sections, and providing higher energy absorption.
v. Its low and non-interconnected porosity diminishes mass transfer making penetration of
liquid/gas or radioactive elements nearly non-existent.
Limitations of RPC:
In a typical RPC mixture design, the least costly components of conventional concrete are basically
eliminated or replaced by more expensive elements. The fine sand used in RPC becomes equivalent to
the coarse aggregate of conventional concrete, the Portland cement plays the role of the fine aggregate
and the silica fume that of the cement. The mineral component optimization alone results in a
substantial increase in cost over and above that of conventional concrete (5 to 10 times higher thanHPC). RPC should be used in areas where substantial weight savings can be realized and where some
of the remarkable characteristics of the material can be fully utilized.
Since RPC is in its developing stage, the long-term properties are not known.
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EXPERIMENTAL PROCEDURE
The present study focuses on developing RPC of compressive strength up to 150 MPa. Along with the
development of RPC, various factors affecting the strength of RPC are studied. The 100100100 mm
size RPC cube specimens were cast by varying the constituent materials and cured at both normal and
high temperature before testing for their strength.
Materials Used in Mix design:
Cement:The Ultra-Tech 53 Grade Ordinary Portland cement (OPC) which complies with IS: 12269-
1987 is used in the present study. Its specific gravity is 3.15
The Silica fume: 945 D from Elkem India Ltd. which complies with ASTM C 1240
95a and IS: 15388-2003 is used in the study. It contains sio2 90%. Maximum size of the particle is
15m. Its specific gravity is 2.2
Quartz Powder- The crushed quartz with particle size ranging from 10m to 45m is used. The
specific gravity of quartz powder is 2.6
Silica Sand: It is yellowish-white high purity silica sand. The particle size of sand is 150m 600m.
Super Plasticizer: The very low w/b ratio required for RPC can be achieved with use of super
plasticizer (SP) to obtain good workability. In this study, the 2nd generation of super plasticizer called
Glenium B-276 Surtec from BASF India Ltd. was used.
To study the influence of the constituent materials, 14 different proportions were
considered by varying water-binder ratio, silica fume and quartz powder content. Cement of quantity
900 kg/m3 was kept constant for all the mixes. The water-binder ratio of the mixes varied from 0.16 to
0.24. Silica fume was added by 15 to 25 percent by weight of cement. 20 percent of quartz powder by
weight of cement was also added for few mixes. Super plasticizer dosage varied from 1 to 4 percent for
all the mixes. Detailed mix proportioning is mentioned in Table 3 from literature.
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Table 3: Proportioning of RPC mixes
MIX TM1 TM2 TM3 TM4 TM5 TM6 TM7 TM8 TM9 TM10 TM11 TM12 TM13 TM14
MATERIAL 15% silica fume 20% silica fume 25% silica fume 15% Silica fume +
20%Quartz Powder
Cement 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Silica
Fume
0.15 0.15 0.15 0.15 0.15 0.20 0.20 0.20 0.25 0.25 0.25 0.15 0.15 0.15
Quartz
Powder
- - - - - - - - - - - 0.2 0.2 0.2
Sand 1.33 1.28 1.24 1.19 1.15 1.16 1.11 0.91 0.98 0.98 0.92 0.82 0.82 0.82
W/B
ratio
0.16 0.18 0.20 0.22 0.24 020 0.22 0.24 0.20 0.22 0.24 0.18 0.2 0.22
SP % 3 2.5 2 1.5 1 3 2.5 2 4 3 2 3 2.5 2
Curing
Regime
Water curing at room temperature and steam curing at 90 0c for 48 hours.
For each batch of concrete, 100 x 100 x 100 mm cubes were cast to evaluate compressive strength
(IS: 10086-1999). The specimens were cured at both normal temperature for 28 days and at 90 C for
48 hours, remaining 26 days at normal temperature. The casted specimens were tested for 7days and 28
days compressive strength.
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RESULTS AND DISCUSSIONS
Arriving at optimal composition with locally available materials is important to achieve the best overall
performance of RPC. Hence, the effects of several parameters on compressive strength were
investigated which include water-to-binder ratio, super plasticizer dosage, different percentage of silica
fume, with and without quartz powder and curing regime. During the study it was observed that the
mixes appeared to be very sensitive to any variation of the chemical composition of the binders or
particle size distribution of the fillers. As there are no standard guidelines for the mix design of RPC,
literature was referred to design the mixes. The silica fume content was varied from 15 to 25 percent by
weight of cement to find the optimum percentage of silica fume in the production of RPC. To study the
influence of addition of quartz powder to RPC, the RPC mixes were also designed with addition of
quartz powder by 20 percent by weight of cement.
Effect of water to binder ratio on compressive strength: The strength of concrete depends upon the
hydration process in which waterplays critical role. The effect of W/b ratio on compressive strength is
shown in fig. 1 at different curing days. From the results we came to know that optimum w/b 0.2 which
gives more compressive strength. The reduction strength at lower w/b ratio is due to insufficient
amount of water for complete hydration process to occur.
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Beyond 0.2 strength is decreasing due to excess amount of water which will create entrainment of air
bubbles.The compressive strengths of all mix proportions at 7 and 28 days are tabulated in Table 4
Table 4: Compressive strength of RPC
Sample No
Normal Curing at 27 C Accelerated Curing at 900C for 48
hours
Compressivestrength at 7 days
N/mm2
Compressivestrength at 28
days
N/mm2
Compressivestrength at 7 days
N/mm2
Compressivestrength at 28
days
N/mm2
TM-1 72 116 81 124
TM-2 70 120 85 132
TM-3 94 128 99 138
TM-4 69 110 78 121
TM-5 66 112 76 119
TM-6 62 93 - -
TM-7 58 95 - -
TM-8 56 87 - -
TM-9 61 96 - -
TM-10 55 90 - -
TM-11 57 85 - -
TM-12 88 112 94 138
TM-13 91 117 105 146
TM-14 85 109 89 122
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Effect of Addition of quartz powder:
Quartz powder improves the filler effect in RPC mix. Quartz powder produce the better result under
accelerated curing condition than that of normal curing condition which is shown in Fig 3. The results
show that the addition of quartz powder increases the compressive strength by 20% under the
accelerated curing condition.
Fig 3: The effect of Quartz powder on compressive strength of RPC
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Influence of Curing Regime:
An adequate supply of moisture is necessary to ensure that hydration is sufficient to reduce the porosity
to a level such that the desired strength can be attained. The effect of curing regime on compressive
strength under various curing ages is shown in Fig. 4. Two curing methods were exercised, one with
normal water curing at 27C, and other at 90C hot water curing for 48 hours. The compressive strength
increased by 10% when cured in hot water as compared to normal curing. This indicates that curing
temperature has a significant effect on the early strength development of RPC. The increased strength is
due to the rapid hydration of cement at higher curing temperatures of 90C compared to that of 27C.
Moreover, the pozzolonic reactions are also accelerated by the higher curing temperatures.
Fig 4: Effect of curing regime on Compressive strength of RPC
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CONCLUSIONS
Following are the conclusions that can be drawn from laboratory results:
a. The maximum compressive strength of RPC obtained in the present study is 146 MPa at
W/b ratio of 0.2 with accelerated curing.
b. In the production of RPC the optimum percentage addition of silica fume is found to be
15% (by weight of cement) with available super plasticizer.
c. The addition of quartz powder increases the compressive strength of RPC up to 20%
d. The high temperature curing is essential for RPC to achieve higher strength. It increases
the compressive strength up to 10% when compared with normal curing.
Reactive Powder Concrete (RPC) is an emerging technology that lends a new
dimension to the term high performance concrete. It has immense potential in construction due to its
superior mechanical and durability properties compared to conventional high performance concrete,
and could even replace steel in some applications.The development of RPC is based on the application
of some basic principles to achieve enhanced homogeneity, very good workability, high compaction,
improved microstructure, and high ductility. RPC has an ultra-dense microstructure, giving
advantageous waterproofing and durability characteristics. It could, therefore, be a suitable choice for
industrial and nuclear waste storage facilities. Its application in India is very little or nil due to there is
no experimental guidelines. Currently research is going on this RPC at CSIR-SERC, Chennai.
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REFERENCES
1. Richard P., Cheyrezy M., Composition of Reactive Powder Concretes, Cement and
Concrete Research, Vol. 25, No. 7, pp. 1501-1511, 1995.
2. Cheyrezy M. et al., Microstructural Analysis of RPC, Cement and Concrete Research,
Vol. 25, No. 7, pp. 1491-1500, 1995.
3. S. Lavanya Prabha., J.K.Dattatreya., Study on stress-strain properties of reactive powder
concrete under uniaxial compression, International Journal of Engineering Science and
Technology Vol. 2(11), 2010, 6408-6416.
4. MK.Maroliya., An Investigation on Reactive Powder Concrete containing Steel Fibers and Fly-
Ash, International Journal of Emerging Technology and Advanced Engineering, Volume 2,
Issue 9, September 2012.
5.
Khadiranaikar R.B. and Muranal S. M., Factors affecting the strength of Reactive Powder
Concrete, International Journal of Civil Engineering and Technology,Volume 3, Issue 2, July-
December (2012), pp. 455-464.
6. Mr.Anjan kumar M U, Dr. Asha Udaya Rao, Dr. Narayana Sabhahit,Reactive Powder Concrete
Properties with Cement Replacement Using Waste Material,International Journal of Scientific
& Engineering Research Volume 4, Issue 5, May-2013.
7. http://www.theconcreteportal.com/
8. http://rebar.ecn.purdue.edu/ect/links/technologies/civil/reactive.aspx
http://www.theconcreteportal.com/http://www.theconcreteportal.com/http://rebar.ecn.purdue.edu/ect/links/technologies/civil/reactive.aspxhttp://rebar.ecn.purdue.edu/ect/links/technologies/civil/reactive.aspxhttp://rebar.ecn.purdue.edu/ect/links/technologies/civil/reactive.aspxhttp://www.theconcreteportal.com/