Evaluation of residual strength and durability aspect of concrete cube exposed to elevated temperature

The study emphasis the effect of elevated temperature on concrete cubes made with M20, M25, and M30 concrete grades. The other variables considered were temperature (100, 200, 400, and 600 °C), duration of exposure (1-h and 2-h) and two types of cooling methods. The mass loss is varied from 0.52 to 6.56% for various temperature and duration of exposure. The mass loss increases as the duration of exposure increased. The porosity ranges from 9.89 to 44.34% and it depends on grade of concrete and exposed temperature. The strength loss ranges from 3% at 200 °C to 57% at 600 °C for air cooled specimen. In quench cooled specimen the loss in strength varies gradually up to 200 °C but at 400 °C the loss in strength was 42%, while the loss was only 32% for air cooled specimen. The obtained residual compressive strength curve from this study was compared with strength curves proposed by various codes.