Effect of ground granulated blast furnace slag as partial replacement in fly ash-based geopolymer concrete

Abstract

Replacement of Ordinary Portland cement (OPC) with geopolymer concrete (GPC) using fly ash is currently utilized in the construction industry to reduce the excessive carbon footprint. However, fly ash has lower strength development compared to OPC. Due to that reason, ground granulated blast furnace slag (GGBFS) is chosen to be blended with fly ash to produce GPC with improved mechanical strength. The analysis of the mechanical properties includes workability, compressive strength and splitting tensile strength of hardened GPC specimens have been carried out. The specimens were prepared with different percentages of GGBFS, from 0 % up to 20 %, partially replacing the fly ash-based GPC. Experimental results showed that the slump, compressive strength and splitting tensile strength of the GPC increase as the GGBFS percentage increases and found to be suitable for structural application.