Elastic strain, Young's modulus variation during uniform heating of concrete

In this work, the variations in elastic strain and Young's modulus of high-performance concrete under constant load and increasing temperatures up to 400°C in accidental conditions are studied experimentally. The same study is carried out under service conditions for high-performance and ordinary concrete subjected to temperatures up to 220°C. The corresponding heating rates are applied until successive constant temperature levels are achieved, and are maintained for several hours to ensure the stabilisation of internal temperature and physico-chemical thermo-dependent processes. The analysis centres on the elastic strain and Young's modulus variations as a function of temperature. The current paper also focusses on the influence of the heating rate. The elastic strain and Young's modulus values are estimated at different temperature levels: 150°C, 200°C, 300°C and 400°C for the high-performance concrete under accidental conditions and 140°C, 190°C and 220°C for both high-performance and ordinary concrete under service conditions.