Investigate physical and mechanical properties of waste red mud and nano-Al2O3 additive to concrete mixed after high temperatures

High-temperature resistance is one of the most important parameters which affect the durability and service life of concrete. This study was carried out in order to produce a concrete with better performance by examining the effect of red mud, which is a waste material, and Nanopowder added on the mechanical properties of concrete under the influence of high temperature. In the first stage, in order to determine the optimum red mud ratio, concrete samples were prepared using red mud at the ratio of 0%, 10%, 15%, and 20%. Then the behavior of samples after heating to 200°C, 300°C, 400°C, 600°C and 800°C were investigated. In the second stage, it is aimed that improve the resistance of concrete to high temperature with Nano-Al2O3 powder based on the optimum ratio of red mud found. Nano Al2O3 powder was also used at the ratio of 0,5%, 1% and 1,25% of the cement and after applying 200, 400 and 600°C temperature the residual strengths were investigated. As result, it can be said that the combined red mud and nano-Al2O3 under high temperature have positive effects on concrete and optimum ratios are 10% red mud and 0.5% nano-Al2O3 contribution. The significant reductions in mechanical properties of concrete occurred with increasing temperature. With the use of red mud which is a waste material concrete, both waste material can be utilized and with the nanopowder additive, the concretes with better performance under high-temperature effect can be produced.