Strength and deformations of high-strength concrete under short-term heating conditions up to + 90°C

The results of experimental researches of short-term heating effect up to +90°C on strength, modulus of elasticity and ultimate strains under axial compression of modified high-strength concrete of C70÷C90 classes were presented. The concrete was obtained with the modifier application MB 10-50C. Temperatures of tests − +20°C; +50°C; +70°C; +90°C. Lifting speed of temperature during heating − 15°C/h. The decrease of concrete strength under axial compression was installed in short-term heating conditions up to +50°C; +70°C; +90°C respectively 20%, 23%, 28% by comparison with tests at the normal temperature. Meanwhile, the modulus of elasticity decreased 18%, 20% and 22% respectively. The ultimate compressive strain of concrete increased 15%, 9%, 11% respectively at the same temperatures. This work was carried out within the frameworks of the grant of FNI Ministry of construction of Russia and RAASN on the topic 7.4.15-18 «Fundamental scientific researches of the elevated temperatures' influence up to 200°C on the characteristics of physical-mechanical and rheological properties of modified high-strength concrete of C70÷C90 classes».