IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017
Available at: www.dbpublications.org
International e-Journal For Technology And Research-2017
Temperature Effect on High Performance Concrete with Fibres KUMUDA V Assistant Professor of Civil Engineering Department, SITAR
Abstract— Present paper reflects that how temperature affects the compressive strength of the concrete in which the cement and fine aggregates replaced with a mineral admixture like fly ash and bottom ash with a constant percentage of steel fibres and carbon fibres to the volume of concrete respectively. In this investigation , concrete of M25 grade is tried using fly ash as partial replacement for cement for cement at 0%,10%, 20%, 30%, 40%, 50% and bottom as partial replacement for fine aggregates at 0%, 10%, 20%, 30%, 40%, 50% with addition of 1% of steel fibres and 0.5% of carbon fibres to the volume of concrete. The effect of the temperature on the compressive strength of SFRC and CFRC was studied using a specimen of size 150mm X 150mm X150mm cubes. After 28 days of curing the specimens were kept in a oven at 1000 C of temperature for 1 hour. The result obtained for SFRC and CFRC were compared with the same grade normal concrete results which was having same W/C ratio. Keywords: Constant Temperature, Conventional Concrete, Compressive Strength, SFRC – Steel Fiber Reinforced Concrete , CFRC – Carbon Fiber Reinforced Concrete , W/C – Water Cement ratio.
density and it reduces its impact on environment. Since1900 the use of fiber to concrete has been experimented. Asbestos fiber were used to concrete in the beginning of 20th century. And in middle, I mean in 1950 the concept of composite of materials came into action. Fibre reinforced concrete was one among. The overall thinking is to get better strength of concrete. To focus on the strength of concrete the steel fiber and carbon fibers were added. By this the strength of concrete can be achieved. The backbone of modern civilization is energy. The major source of energy is electric power from thermal power station. 70% of the energy electricity is being generated by burning fossil fuels. Out of 70% nearly 61% is produced by coal fired plants. This results nearly 100 tons of ash produced per year. This ash can be disposed off either dry or wet to a near by open area. Or by grounding both bottom ash and fly ash we can dispose. Or mixing with water we can pump it into artificial lagoon or dumping into yards. Through there is a report that will cause environmental pollution. Due to this reason the experiment research and investigating is on. The effect of use of bottom ash as a replacement of fine aggregates. To avoid the pollution bottom ash came into use.
INTRODUCTION In construction activities concrete is the most commonly used material. When hardened it becomes strong and durable but it will be plastic and malleable in its fresh state. It is good in compression but weak in tension. Its strength can be achieved in tension by providing reinforcement. The aggregates are the major components of concrete. A broad range of environment and social consequences are produced by the use of cement and manufacture. The consequence is both harmful and acceptable. Production of cement causes pollution due to gas emissions. Attempts have been done to reduce green house gas. So by substituting conventional clinker with industrial by products like fly ash and bottom ash cement industries have taken actions. The use of industrial wastes is taking importance as additives, by this they increase strength,
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PROBLEM DEFINITION In this present experimental work, the properties of concrete are thoroughly studied for M25 grade with fibres as reinforcing materials. In addition to this some of the industrial wastes (fly ash7&bottom6ash) obtained5from thermal5power plant having a little cementitious7properties are substituted with cement and fine aggregate respectively. Both fly ash and bottom ash are replaced with cement and sand with following variations of 0%, 10%, 20%, 30%, 40% and 50% by weight of cement and sand respectively. The fibres used for this study are steel and carbon at constant percentage of 1% and 0.5% volume of concrete respectively. Temperature effect on the compressive strength of fiber reinforced concrete was studied in this work.
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METHODOLOGY The temperature effect of SFRC and CFRC was determined at 28 days by using cubes of size 150 X 150 X 150mm IMPLEMENTATION This test was conducted to determine the effect of temperature on strength of concrete. 150mmx 150mm x150mm cubes are used to find out the compressive strength affected by temperature. After demoulding the cubes from moulds, it has kept for curing for 28 days respectively. After0curing time the cubes5taken out from the curing tank and kept that cubes in oven for one hour at 100 0C, the temperature was kept constant for complete experiment. After oneghour take out the cubes from oven, let it to be cool. After sometimes the compressive strength was tested and value is recorded. The compressive strength is recorded for 28 days.
Loss in compressive strength due to temperature effect =
RESULTS Temperature effect of normal concrete and fibre reinforced concrete with additives was determined by using cubes of size 150mm x150mm x 150mm at constant temperature. The values of compressive strength affected by temperature is tabulated in Table.1.1 and 1.2 and variation of strength is as shown in Fig.1.1 and 1.2.
Table.1.1 Replacemen t of FA & BA in % with 1% of Steel Fibres
Initial Compressive Strength in N/mm2
Final Compressive Strength in N/mm2
Loss in Strength of SFRC in %
CC
37.21
33.86
9.00
38.33
34.88
9.12
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10%
39.54
35.98
9.21
20%
39.01
35.50
8.99
30%
35.55
32.35
9.10
40%
32.00
29.44
8.89
50%
28.88
26.25
8.56
(fc – fcl ) / fc x 100
Where fc = Cube Compressive strength in N/mm2 fc1= Cube Compressive strength after temperature effect in N/mm2
0%
(With fibres)
2
Table.1.2 Replacemen t of FA & BA in % with 0.5% of Carbon Fibres
Initial Compressive Strength in N/mm2
Final Compressive Strength in N/mm2
Loss in Strength of CFRC in %
CC
38.22
35.16
8.00
0% (With fibres)
38.53
34.35
7.98
10%
38.87
34.75
7.15
20%
39.25
36.11
8.00
30%
38.25
35.19
8.12
40%
31.55
29.05
7.92
50%
27.11
24.94
7.95
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IDL - International Digital Library Of Technology & Research Volume 1, Issue 5, May 2017
Available at: www.dbpublications.org
International e-Journal For Technology And Research-2017 FA and BA goes on increasing. More strength reduction in case of SFRC compare to CFRC. SCOPE FOR FURTHER STUDY Temperature effect on concrete can be finding out by varying the temperature values.
Other industrial by products can be use as replacement of constituent materials of concrete.
Fig.1.1
Fig.1.2 CONCLUSION 1. A gradual decrease of compressivehstrength was observed for both the fibres, but the temperature effect was found to be decreasing as the FA and BA percentage was increasing. 2. For SFRC at 50% replacement there 22.50% decrease in temperature effect when compared to CC and similarly 29.89% reduction was obtained for same % of CFRC. 3. This due to the reason that FA and BA are industrial by-products which already have more heat resisting power than conventionalkconcrete and hence as the FA and BA percentage was increasing the temperature effect was found to be decreasing. 4. Temperaturekeffect results shown that there is consistence decrease in % loss of strength as % of IDL - International Digital Library
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REFERENCES 1. P. Aggarwal, Y. Aggarwal and S.M. Gupta ―Effect of Bottom Ash as Replacement of Fine Aggregates in Concrete‖, Asian Journal Of Civil Engineering (Building And Housing) Vol. 8, No. 1 (2007). 2. Saravana Raja Mohan. K and Parthiban. K ―Strength and Behaviour of Fly Ash Based Steel Fibre Reinforced Concrete Composite‖ International Journal of Civil and Structural Engineering , Vol. 2, No 1,(2011) ISSN 0976 – 4399 . 3. G.Murali, C.M. Vivek Vardhan, P. Sruthee and P. Charmily , ―Influence of Steel Fibre on Concrete‖, International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 3, May-Jun 2012. 4. M.A.Pathan and M.A.Jamnu. ―Compressive Strength of Conventional Concrete and High Strength Concrete with Temperature Effect‖ International Journal of Advanced Engineering Research and Studies IJAERS/Vol. I/ Issue III/April-June, 2012/101-102. 5. R.Vasusmitha and Dr.P.Srinivasa Rao , ―Effect of Elevated Temperature on Mechanical Properties of High Strength Self Compacting Concrete‖ International Journal of Engineering Research &
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Technology (IJERT) Vol. 1 Issue 8, October - 2012 ISSN: 2278-0181 6. Gunavant K. Kate and Pranesh B. Murnal ―Effect of Addition of Fly Ash on Shrinkage Characteristics in High Strength Concrete‖, International Journal of Advanced Technology in Civil Engineering, ISSN: 2231 –5721, Vol.-2, Issue-1, 201.
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