The effect of elevated temperature on the properties of SCC's produced with different types of fibers

Abstract

Self-compacting concrete (SCC) has various advantages such as improved workability and physical properties with advanced compressive strength against traditional structural concretes. However, under high temperatures, the dense composite structure with a compact matrix can facilitate the deterioration of concrete. This study aims to determine the effect of polypropylene, steel, and glass fibers on the mechanical and physical properties of SCC at elevated temperatures. In the fibrous mixtures, polypropylene fiber was used as 0.1%, 0.3%, and 0.5%, steel fiber was used as 0.1%, 0.2%, and 0.3%, and glass fiber was used as 0.1%, 0.3%, and 0.5% by volume of concrete. In addition, a fiber-free SCC control mix was produced to determine the variation of the properties of SCC mixtures. For this purpose, ten SCC mixtures were designed to estimate the workability and hardened properties of the SCC mixtures. The effect of high temperature was investigated by performing ultrasonic pulse velocity, compressive strength, splitting tensile strength, and apparent porosity tests on hardened SCC mixtures that were exposed to 200, 400, and 600 degrees C. The microstructure of these specimens is observed by using Scanning Electron Microscopy (SEM) on the cross-sections obtained from the hardened SCC mixtures. As a result of the study, it was observed that the use of steel or glass fiber (up to 0.5% by volume) improved the mechanical properties of SCC up to 600 degrees C. However, these improvements were not seen when using polypropylene fiber in the same fiber volumes.