Experimental Studies on Geopolymer Concrete

Abstract

Concrete is the most ubiquitous and highly utilized building material on earth. Production of conventional concrete requires cement and aggregates, in which cement is an eco-detrimental element. There is a need to subside the usage of cement composites to mitigate carbon emissions. A sustainable building material which can substitute cement composite is necessary and geopolymer concrete (GPC) is one such substitute. GPC utilizes marginal materials like fly ash, Ground Granulated Blast Furnace Slag (GGBS), kaolin, etc., as the binder instead of cement. In this study, GGBS was used as a binder along with conventional aggregates like river sand and crushed stone to prepare GPC. Alkaline solutions of 8, 10, and 12 molarities were prepared using pellets of sodium hydroxide and a solution of sodium silicate. GPC specimens are tested for fresh properties, hardened properties, and durability. The rate of strength gain was swift due to the usage of GGBS as the binder. The maximum strength of 81.43 MPa was achieved at 28 days for a 12-molar mix. Mechanical strength increased with an increase in molarity of alkaline solution, but the workability decreased accordingly. Split tensile strength and flexural strength were proportional to compressive strength. The results depict that the geopolymer concrete was resistant to chemical ingress and water penetration. With the increase in molarity, resistance to the corrosive environment was high. Thus, geopolymer concrete is a sustainable alternative to conventional concrete.