An experimental study on the performance of self-compacting lightweight concrete exposed to elevated temperature

This paper presents an experimental study on the spalling characteristics, mass loss ratio, ultrasonic pulse velocity, compressive strength and flexural strength of self-compacting lightweight concrete (SCLC) at elevated temperature. Four types of SCLC specimens with and without polypropylene fibres (PPFs) and one type of normal concrete (NC) specimens were cast and tested. Based on the experimental observations and results, it was found that, compared with NC, SCLC spalls at a lower temperature but maintains a higher residual strength. For all the concretes the peak mass loss ratio increased but the relative ultrasonic pulse velocity decreased with the rise of temperature. At a given elevated temperature, the relative compressive strength and flexural strength of SCLC was larger than those of NC. The addition of PPFs greatly reduced the risk of spalling of SCLC. The thermal damage and the loss in residual mechanical properties of SCLC with PPFs were smaller compared with that without PPFs.