Lightweight Self-Consolidating Concrete Exposed to Elevated Temperatures

Abstract

Exposing concrete to high temperature causes progressive breakdown of the cement gel structure and consequently severe deterioration and loss in the structure’s load bearing capacity. This paper presents an experimental study on the mechanical and physicochemical properties of lightweight self-consolidating concrete (LWSCC) subjected to high temperatures. Four LWSCC mixes and one normal-weight self-consolidating concrete (NWSCC) were tested. The specimens underwent two different tests: a fire test and a thermal characterization test. The first is the ISO fire test, which consists of heating the prismatic specimens according to the standard fire curve up to 600°C. The second test is the thermal characterization test, which consists of heating the specimens at a rate of 1°C/min up to 400°C. Ultimate and residual compressive strength, loss of mass, density, water porosity, spalling characteristics, and other physicochemical properties before and after the fire tests were recorded. The LWSCC performed differently from the NWSCC with respect to mechanical properties and spalling resistance. Scanning electron microscopy and backscatter electron images analysis were performed to study the microstructure of both heated and unheated specimens.