Effect of Clay Brick Dust (CBD) on compressive strength of fly ash based geopolymer mortar

Abstract

Geopolymer is considered as an alumino-silicate material which can be used to replace Ordinary Portland Cement (OPC). There are many alumino-silicate materials found in nature and some of them are FlyAsh (FA), Ground Granulated Blast furnace Slag (GGBS), rice husk ash etc. Currently, there is a growing potential to utilize Clay Brick Dust (CBD) in the development of Geo Polymer Concrete (GPC). CBD contains high percentage of silica and alumina content. The current study is to find the effect of CBD on the compressive strength of FA based Geo Polymer Mortar (GPM) cubes. Initially the mix design of FA based GPM was carried out for 12 mixes and Na2SiO3 / NaOH ratio was fixed to 2.5. Then the effect of CBD on the compressive strength of FA based GPM was examined for 18 mixes by varying molarities of sodium hydroxide from 8M to 12M and by varying the percentage replacement of FA with CBD from 5% to 30%. There was an increase in the compressive strength of mortar cubes by 5.18% when 15% of FA was replaced by CBD. The best durability properties were also obtained for the same replacement percentage.