Experimental research for the effect of high temperature on the mechanical properties of steel fiber-reinforced concrete

Abstract

It is widely known that addition of steel fibers to concrete improves properties of concrete having brittle behavior. This affects the behavior in a positive way particularly by increasing ductility of the concrete. In this study, the results of the effect of high temperature on steel–fiber concrete were investigated. RC80/60 BN type steel–fibers were added to experimental concrete as in the rates of 0%, 0.5%, 1% and 1.5% by volume and concrete cylinder samples with 7, 28 and 90-day were tested. Produced cylinder samples were exposed to 900°C, 1000°C, 1100°C and 1200°C temperatures in the furnace. The effect of temperature was applied to samples within 6h in experiments.In this study, compressive strength, modulus of elasticity and toughness values of fiber-concrete were given comparatively according to different fiber ratios, concrete age and varying temperature effects. Consequently, compressive strength, modulus of elasticity and toughness values of fiber-concrete substantially decreased by the effect of high temperature as it was expected. When it was examined the results with regard to percentage of steel fiber, samples of 1.0% fiber additive had specifically the lowest of compressive strength losses. Additionally in comparing results of compressive strength losses on high temperature effect were lower at 900°C and 1000°C than at 1100°C and 1200°C temperatures. Determined results of 1100°C and 1200°C temperatures were closed with each other. Namely compressive strength values reached the lowest value after 1100°C.