Effect of temperature on the mechanical properties of self-flowing low cement refractory concrete

Abstract

Physical and mechanical tests are applied to the samples prepared from bauxite/fused brown corundum 50%, SiC 15%, calcined alumina 15%, reactive alumina 10%, calcium aluminate cement (CAC) 5%, micro silica 5%. Phases of the samples heat-treated at 110°C, 1000°C, and 1500°C are investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Bauxite-based samples, which have higher porosity than corundum-based samples, show higher cold crushing strength (CCS) and modulus of rupture (MOR) than corundum-based samples. Samples fired at 1000°C have higher CCS than those fired at 1500°C for both types of samples. The same behavior is not observed for modules of rupture of bauxite-based samples, but only observed for fused corundum-based samples. It is found that hot modules of rupture of bauxite-based samples at 1000°C and 1500°C are better than corundum-based samples. The possible reason for better properties of bauxite-based samples is the new mineral phase formation obtained by XRD results and pore size distribution.