“Experimental Study on Fly Ash based Geopolymer Concrete with Replacement of Sand by GBS”

Abstract

The objective of this research work was to produce a carbon dioxide emission free cementitious material. The geopolymer concrete is totally cement free concrete. In this present study the main limitations of fly ash based geopolymer concrete are slow setting of concrete at ambient temperature and Granulated Blast Furnace Slag (GBS) as replacement for natural sand. Fly ash and alkaline activator undergo geo polymerization process to produce alumina silicate gel. Alkaline solution used in the present study for the combination of sodium hydroxide and sodium silicate with a ratio of 1:2.5. A 13 Molarity solution was taken to prepare the mix and maintaining the alkaline binder ratio as 0.40. The solution for different mix Id i.e. and G100S0 (Where G and S are, respectively, GBS and Sand and the numerical value indicates the percentage of replacement of natural sand by GBS). The cube specimens are taken of size 100 mm x 100 mm x 100 mm. Ambient curing of concrete at room temperature was adopted. In total 66 cubes were cast for different mix Id and the cube specimens are tested for their compressive strength at age of 7 days and 28 days respectively. The strength of geopolymer concrete was increased with increase in percentage of GBS in a mix. It was observed that the mix Id G100S0 gave maximum compressive strength of 74.33 N/mm2. Also the splitting tensile strength and flexural strength for the mix G100S0 was done. Geopolymer concrete is revolutionary sustainable that will pave the way for green building.