Residual Mechanical Properties of Self-Compacting Concrete Exposed to Elevated Temperatures

Abstract

This study aims to investigate the residual mechanical properties (compressive strength, modulus of rupture and dynamic modulus of elasticity) of selfcompacting concrete (SCC) exposed to elevated temperatures ranging from (100- 800 oC) as well as studying its fresh and hardened properties at normal temperature. Also it aims to study the influence of high reactivity metakaoline (HRM), as a partial replacement by weight of cement, for improving its mechanical properties after and before exposure to elevated temperatures. The concrete specimens were subjected to a temperature range of (100, 200, 400, 600 and 800oC) with an exposure duration of 2-houres. The test results showed that the performance of SCC containing HRM is higher than that of SCC without HRM , where the residual compressive strength of HRM SCC after an exposure to a temperature level of (800oC) was 73.2% while for the normal SCC was 65% from their original strength .At the same exposure temperature (800oC) , the loss in modulus of rupture is higher than that of compressive strength , the difference was between (2% - 12.4%). Also the reduction in dynamic modulus of elasticity (Ed) is higher than that of compressive strength and modulus of rupture ,where the residual (Ed) was between (47.3% - 63.5%) after 800oC exposure.