Compressive Strength of Lightweight High-Strength Concrete Subjected to High Temperatures

The effects of high temperature on mechanical properties of high strength concrete were experimentally investigated in this paper. The effect of elevated temperatures ranging from 20 to 700°C (68 to 1292°F) on the material mechanical properties of normal-weight and lightweight aggregate high-strength concrete of 60 MPa grade was evaluated. Tests were conducted on O100 × 200 mm (3.94 × 7.87 in.) cylinder specimens. The specimens were tested under both stressed and unstressed conditions. The specimens were preloaded to 20 and 40% of their ultimate compressive strength at room temperature and subjected to temperatures ranging from 100 to 700°C (212 to 1292°F), and the compressive strength compared to that observed at 20°C (68 °F).