Scanning electron microscopic evaluation of self-compacting concrete spalling at elevated temperatures

Abstract

This paper reports the effect of addition of Polypropylene (PP) fibers in the performance of Self-Compacting Concrete (SCC) under elevated temperatures. Various SCC mixtures were made with PP fiber at 0.0, 0.05, 0.10 and 0.15% by volume added. The specimens were exposed to elevated temperatures (200°C [392°F], 400°C [752°F] and 600°C [1112°F]). The microstructure of the matrix was investigated. This study concluded that the high temperatures have a coarsening effect on the microstructure of SCC with the addition of PP fibers. It was reported that PP fibers reduced explosive spalling of SCC above 0.05% by volume and increased the number of voids in the microstructure significantly.