Influence of NaOH concentration on Mechanical Properties of Fly Ash-Slag based Geopolymer Concrete

Abstract

Geopolymers are suitable substitutes for ordinary Portland cement (OPC) as a binder for reducing carbon dioxide emissions and accomplishing effective waste recycling. The majority of previous studies were focused on fly ash-based heat-cured geopolymer concrete (GPC). This study mainly focuses on the development of ambient-cured GPC with the utilization of fly ash (FA) and ground granulated blast furnace slag (GGBFS) as a binder. The NaOH molarity was varied within a range of 8 M to 14 M to investigate its impact on the fresh and hardened mechanical properties. The workability, compressive strength, and flexural strength were investigated at 7 and 28 days. The test result indicated that the workability decreased with an increase in NaOH molarity from 8 M to 14 M. The optimum compressive strength of 44.15 MPa and flexural strength of 1.99 MPa were achieved at NaOH molarity of 12 M and 14 M, respectively.