Experimental investigation of alkali-activated hybrid geopolymer concrete

To encourage sustainable development, geopolymer concrete (GPC) is prepared using three by-products viz, ground granulated blast furnace slag (GGBFS), fly ash (FA) and rice husk ash (RHA), along with basalt fibres (BSF). GGBFS, FA and RHA are employed as binder materials in proportions of 40, 30 and 30%, respectively. Alkali activators are NaOH at 14 M concentration and Na2SiO3. The BSF is utilised in varying percentages as 0 in the control mix (FRGB0 and TFRGB0) and 0.1,0.5, 1,1.5, 2 and 2.5% (by weight) in the rest of the samples. 200 samples were cast and divided into two categories and cured for seven and twenty-eight days in ambient circumstances (category 1) and at an elevated temperature of 90 degrees C (for 48 h) in the oven following ambient curing (category 2).The workability of all the GPC mixes was found good in terms of Vee Bee seconds, compaction factor and slump values. For categories one and two specimens, compressive, flexural and split tensile strength increased significantly with BSF 1%, and there is a significant increase in strength of category two specimens as compared to category one specimens. The water absorption also decreased up to addition of 1% BSF in the mix and beyond that, it showed an increase.