Shear Behaviour of Glass Fibre-Reinforced Geopolymer Concrete

Abstract

Experimental investigations were carried out on shear behaviour of geopolymer-reinforced concrete beams with and without fibres. The mix is composed of ternary blend of mineral admixtures, ground-granulated blast furnace slag (GGBS), silica fume, metakaolin and fly ash. In all the mixes, the amount of GGBS is kept constant and other mineral admixtures such as silica fume, metakaolin and fly ash are varied in different proportions. Two concentrations of molarities, namely, 6 and 10 M of NaOH solution are considered in the present study to investigate the shear behaviour of geopolymer concrete beams with and without glass fibres. Several beams were cast for different mixes and the responses were studied under four-point bending static loading. Among the various mixes, it was found that the mix of 10 M, i.e. 70% GGBS + 12% fly ash + 10% silica fume + 8% metakaolin performed well with and without fibres. Many cracks were developed for the case of fibre-incorporated beams signifying the contribution of fibres in terms of higher energy absorption and improved ductility. There is no significant difference is observed in terms of load carrying capacity, first crack load and deflection of 10 M mixes compared to 6 M mixes.