Investigation on modulus of elasticity of powder-activated geopolymer concrete

Abstract

Geopolymer is an inorganic binder, synthesised by the activation of aluminosilicate compounds by strong alkali solution. Previous researches suggested that geopolymer concrete possessed superior mechanical properties over ordinary Portland cement (OPC) concrete; however, modulus of elasticity was found lower than OPC concrete of same grade. Two types of powder-activated geopolymer binders were used to produced geopolymer concretes of four different grades and two workability levels; normal and super-workable. Development of compressive strength and modulus of elasticity geopolymer concretes were investigated at ambient curing and compared with OPC concrete of same grade. Early age compressive strength of geopolymer concrete was lower than OPC concrete of same grade; however, the ultimate strength was significantly higher. The modulus of elasticity of geopolymer normal-workable concrete was similar to OPC concrete of same grade and complied with AS-3600. However, modulus of elasticity of geopolymer super-workable concrete was significantly lower than normal-workable concrete of same grade.