Post heat exposure behaviour of reinforced concrete beams

Abstract

Synopsis Consideration is given to the behaviour of reinforced concrete beams after subjection to elevated temperatures in the range 20 to 800°C. Prismatic concrete beams reinforced with plain mild steel and tor bars were cast using the same concrete mix and water: cement ratio. Each beam was heated to a particular temperature and held at that level for one hour prior to coolingfreely in air to ambient temperature and then testing to failure under four point loading. Temperature distributions within the beam sections were monitored during the heating cycle, and bond-slip as well as load-deflection responses were examined in the residual heat treated condition. Crack pattern development was studied arising from both thermal and loading effects and the influence of bar type and grouping were examined.