Evaluation of high-performance self-compacting concrete using alternative materials and exposed to elevated temperatures by non-destructive testing

Abstract

The present study quantitatively evaluates the residual density, compressive strength, flexural strength and ultrasonic pulse velocity (UPV) of high-performance self-compacting concrete (HPSCC) after exposure to elevated temperatures. The produced HPSCC is expectably an eco-efficient concrete since it is produced incorporating coarse recycled concrete aggregate and alternative waste materials as partial replacement of coarse natural aggregate and cement respectively. The waste materials are waste fly ash, perlite and cellular concrete powders. Tests of 21 HPSCC mixes were conducted to check the correlation between the relative residual UPV and other properties of concrete after exposure to elevated temperatures ranging from 20 °C to 800 °C. Considering the relative residual values instead of the absolute ones makes the quantitative evaluation by using UPV more feasible for the evaluation of the residual strength of concrete structures after exposure to elevated temperatures, where in this case the effect of the mix composition of concrete is small. General equations are proposed for relative residual density, compressive strength, flexural strength and UPV of concrete after fire exposure. Through the results, the effect on the performance of HPSCC after exposure to elevated temperatures of coarse recycled concrete aggregate and alternative waste material has been investigated and discussed. It is also found that the relative residual UPV is correlated to the strength and density of HPSCC after fire exposure.