Optimum mix for the geopolymer concrete

Optimum mix for the geopolymer concrete

Abstract

Geopolymer concrete utilizes an alternate material including fly ash as binding material in place of cement. This fly ash reacts with alkaline solution (e.g., NaOH) and Sodium Silicate (Na 2 SiO 3 ) to form a gel which binds the fine and coarse  aggregates. Since  Geopolymer concrete is the emerging field, the guidelines from the Bureau of Indian Standards are yet to be formulated.An attempt has been made to find out an optimum mix for the Geopolymer concrete.Concrete  cubes  of  size  150  x  150  x  150  mm  were  prepared  and  cured  under  steam  curing  for  24  hours.The compressive strength was found out at 7 days and 28 days.The results are compared.The optimum mix is Fly ash: Fine aggregate:Coarse aggregate (1:1.5:3.3) with a solution (NaoH & Na 2 SiO 3  combined together) to fly ash ratio of 0.35.High and  early strength was obtained in the Geopolymer concrete mix.

 Keywords: Geopolymer concrete, optimum mix ratio