Abstract
The effects of high temperature on the mechanical properties of high strength concrete (HSC) have been studied experimentally at various temperatures that covered the 20°C and the 100 to 800°C temperature range at 100°C increments. Concrete specimens of HSC were tested under compression at ages about 3, 6 and 12 months. The stress-strain curve of HSC under compression test exhibits brittle properties below 500°C, and ductile properties above 500°C. The compressive strength decreases to about 60-70% of the strength of room temperature at 100°C, increases up to about 80-90% of the strength of the room temperature at 200°C and gradually decreases with further increase of temperature. From these test results (including Ref.9 test results), mathematical expressions of the compressive strength, the strain at compressive strength, the stress-strain relationship and the modulus of elasticity were proposed. The comparatively good correlation between predicted and experimental results indicates the adequacy of the expression of stress-strain relationship.
