Performance of Fly ASH Based Concrete with Fiber under Elevated Temperature

Abstract

Concrete when exposed to elevated temperature, mechanical properties gets reduced which results in structural failure. The strength of concrete is improved by means of addition of pozzolonic material. Pozzolonic material reduces the pores in the concrete structure and hence improves durability. Here, flyash is added as it facilitates the replacement of cement with flyash to a greater extent. In addition to that fibers like as steel and carbon fibres are added in concrete to achieve better workability, tensile strength, compressive strength, Thermal resistance. The aim of this paper is to experimentally investigate the behaviour of fiber reinforced concrete subjected to elevated temperature at 250^oC, 500^oC sustained for a period of 2 and 3 hours. The cement is replaced by 10, 20 and 30% of flyash by weight of cement. The cubes and cylinders were cast and cured under normal conditions for a period 28, 58 and 90 days and it is tested for their compressive and split tensile strength respectively. The test result shows that the maximum strength was attained at 20% of replacement of cement. The cube specimens after curing subjected to a temperature of 250^oC and 500^oC for duration of 2 to 3 hours were also tested for its compressive strength. Analytical model was also developed using ANSYS. The results obtained from finite element analysis shows good agreement with that of experimental results.