Effect of Silica Fume in the Mechanical Properties of Ambient Cured GGBS Based Geopolymer Concrete

Abstract

Geopolymer concrete (GPC) is an emerging sustainable construction material alternative to the conventional Ordinary Portland Cement Concrete (OPCC), which utilizes the cementitious properties of industrial or agricultural by-products such as fly ash, Ground Granulated Blast furnace Slag (GGBS), silica fume, red mud, rice husk ash (RHA) etc. activated by an alkaline solution and thereby reduce the demand for cement and the related environmental issues. In the present work, Ground Granulated Blast furnace Slag (GGBS) is blended with silica fume in various proportions at ambient temperature condition to produce the geopolymer concrete and the mechanical properties are investigated and compared with OPCC of M30 grade. Sodium hydroxide and sodium silicate solution are used as alkali activators throughout this work. The compressive strength test results show that the GGBS based geopolymer concrete (GGPC) gives high compressive strength concrete at ambient temperature conditions and the inclusion of silica fume at various percentages (10, 20, 30, 40, 50 and 60%) significantly reduced the compressive strength. However, a considerable increase in workability was observed with increasing percentage of silica fume in GGPC. The test results of GGPC blended with silica fume at 40% are comparable to OPCC of M30 grade.