Strength of Self-Compacting Concrete Produced With Cement Kiln Dust Exposed to Elevated Temperature

Abstract

This experimental research is employed to observe the mechanical properties and hardened efficiency of self-compacting concrete (SCC) with different cement kiln dust (CKD) content after being applied to elevated temperatures at 300°C, 500°C and 700°C. Rheological, hardened, and mechanical properties of concrete which have been partially replaced by 10%, 20% and 30% of CKD (SCC-CKD) were investigated. The results disclosed that partially replaced cement by CKD in the SCC (SCC-CKD) lowered its passing and filling ability marginally, while segregation resistance increased. The remaining mechanical and hardened characteristics of heated SCC Specimens were measured. Specimens were exposed to elevated temperature (2 hours) by an electric heating furnace to temperatures between 300 and 700 °C at the age of 28 days. After samples were cooled, tests on several aspects of compressive and indirect tensile strength and loss in weight were performed out. Moreover, ultrasonic pulse velocity was measured. The experiment findings reveal extreme strength and density loss due to concrete degradation for all SCC samples after being heated to 700 °C. At high replacement levels of CKD, there is more decrease in the remaining strength. Compared to the reference mix (SCC-R), the compressive strength of (SCC-CKD20%) mix at 700 °C decreased by 29 %. For all heating degrees, control mixture (SCC-R) samples exceeded replaced (SCC-CKD) samples in respect of residual characteristics. Throughout this context, current research aims to determine how elevated temperatures affect the mechanical strength and hardening properties of SCC made with CKD as a partial cement replacement.