Influence of Cooling Type, Duration and Cyclic Heating on Strength of Concrete Exposed to Elevated Temperatures

This paper highlights the performance of concrete exposed to elevated temperatures with different cooling conditions, duration and number of cycles of exposure. Tests are conducted on concrete cubes exposed to different temperatures up to 1000°C and studied the influence of air and water cooling types, duration of exposure and number of cycles in sustaining the strength. It is observed that the residual compressive strength is decreased with increase in temperature. The strength reduction is observed more in water cooled cubes than air cooled cubes. Majority of strength loss is observed within the first half an hour of exposure time. At low temperatures, the influence of number of repetitions of heating did not cause any reduction in strength. At high temperatures, maximum reduction of strength is observed in first cycle of heating and very minimal for the remaining cycles.