Effects Of Elevated Temperature On Compressive And Split Tensile Strength Of Plain Concrete Mix With Steel Slag As Coarse Aggregate

Abstract

Concrete will not burn when it under fire ( Elevated Temperature) and it also will not emits any flumes but there will be chemical reactions taken place , this proposed work is an effort underway to investigate the impact of enhanced temperatures on different properties of concrete with steel slag as an additive. At present, the amount of slag deposited in storage yard adds up to millions of tons/year leading to the occupation of farmland, around industrial area and may serious pollution to the environment, as a result of the rapid growth in the steel industry. In Ethiopia, the amount of waste slag deposited in the storage yard adds up to 1.5-3 tons/day. This research investigates the behavior of using steel slag as partial to fully coarse aggregate replacement with different percentages of 0%, 20%, 40%, 60%, and 100% in concrete. For each replacement the compressive and split tensile strength of the concrete were evaluated at room temperature, 200°C, 400°C, 600°C and 800°C. From the results, it can be observed that the strength reduction in the concrete depends more on the temperature to which it is subjected rather than the percentage of replacements of slag aggregates. It can be inferred that the natural coarse aggregates can be replaced by steel Slag aggregates of 60% for up to a maximum 200°C, of 40% and 20% for up to a maximum of 400°C. from this 40% replacement is advisable if concrete is exposed to a temperature of up to 200°C for both compressive and tensile strength of concrete. Because there may be apersonal error in actual site work to increase or decrease the percentage of replacement and the fire is not fixed may increase. Therfore 40% replacemet to a maximum temperature of 200°C is recommended. The proposed constitutive model was validated by the comparison of the simulation results of the uniaxial compression tests of concrete at different temperatures with the corresponding test results. From the results, The peak damage-strain of simulation was smaller than tested result, while the peak stress-strain of simulation was larger than the tested result when the temperature was increased. At 800°C, the peak stress-strain value of simulated damaged concrete is 10% greater than of tested result, while the peak damage strain value of tested result of danmaged concrete is 3.1% greater than the simul