Investigation of Flexural Strength and Toughness of Fly Ash Based Geopolymer SIFCON

Geopolymers are environmentally friendly construction materials produced by the use of silica and alumina-rich powder materials with high alkaline solutions. Reinforcing the matrix phase with continuous or discontinuous fibers has been applied for many years to increase the tensile strength and energy absorption capacity of composite materials developed for different applications. SIFCON composites are one of them, and they are produced by placing the fibers in the mold and then filling the mold with very fluid matrix phase. However, there is a need for research on the use of geopolymer matrix in SIFCON production. In this study, fly ash-based geopolymer SIFCON composites containing 5% by volume steel fibers were produced and their flexural strength, compressive strength and toughness properties were investigated on both samples that were not exposed to high temperature and exposed to 900°C. In addition, cement-based conventional SIFCON composites with similar flexural strengths with the geopolymer SIFCON were used for comparison. It was determined that the fly ash-based geopolymer SIFCON had higher flexural strength and toughness values than that of the cement-based SIFCON after exposing to high temperature. In addition, for a given flexural strength, geopolymer SIFCON showed a higher compressive strength than that of conventional SIFCON. © 2022, TUBITAK. All rights reserved.