Investigation of the Behaviour of Geopolymer Mortar with Fly-Ash under High Temperature

Geopolymers belong to a range of inorganic polymeric materials formed by activating silica aluminium rich minerals. Silica-aluminium rich industrial wastes like fly ash etc. are activated with alkaline or alkaline-silicate solution at ambient or higher temperature to get Geopolymers. The objective of the present research is to investigate the effect of different synthesizing parameter on the hardened properties fly ash based geopolymer mortar exposed to different Elevated temperature level. An experimental investigation on low calcium fly ash based geopolymer mortar, was undertaken. Percentage of Na2O was taken 8 % and 10 %. SiO2 / Na2O ratio was varied from 1 to 1.6. Sand to Fly ash ratio was kept 21, 11, and 12. Curing temperature and curing time were 800C and 72 hours respectively. After seven days, specimens were heated in oven at 2000C, 4000C & 5500C for four hours and then kept in air for cooling. The effect of various synthesizing parameters at different temperature exposure on different properties such as Compressive strength, workability test & Apparent porosity have been studied and the results were presented in the tabular form. It was observed that the geopolymer mortar is quite temperature resistant & some reduction in compressive strength was observed.