Behaviour of gneiss and basalt aggregate in normal concrete subjected to high temperatures

This work aims at analyzing the high temperature behaviour of normal concrete containing quarry aggregates commonly used in Cameroon. Gneiss aggregate concrete (C-SG-GG) and basalt aggregate concrete (C-SB-GB) were formulated. Specimens were subjected to different heating-cooling cycles of 150, 300, 450 and 600°C at a low heating rate of 1°C/minute to obtain the residual properties; and a faster heating rate of 10°C/minute up to 600°C to study the thermal sensitivity. The thermal expansion coefficient, physical and mechanical properties of the concrete samples were analyzed. The results showed mineralogical properties of aggregates had an effect on mechanical behaviour. The thermal expansion coefficient of basalt concrete is much lower than that of gneiss concrete. In this study, basalt aggregate concrete presented a better behaviour at high temperature than gneiss aggregate concrete.