Experimental Investigation on Flexural Behaviour of Reinforced Geopolymer Concrete with and without Glass Fibres

Abstract

Experimental investigations were carried out on flexural 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 varying proportions. Two different molarities, namely, 6M and 10M of NaOH and Na2SiO3solution were considered to study the behaviour of geopolymer concrete beams with and without fibres. Beams were cast for various mixes and the behaviour was studied under static standard two point loading. From the flexural experiments, it was found that the first crack load varied from 24 kN to 46 kN and the final failure load varied from 71 kN to 139 kN. It was found that the ultimate load and the corresponding deflection is increased by about 5–10% for the case of beams with fibres. Many multiple cracks were observed in the case fibre incorporated beams which shows the higher energy absorption and improved ductility. It was further noted that for the case of 10M mix beams, there is no significant difference in terms of load carrying capacity, occurrence of first crack load and deflection compared to 6M mixes.