Flexural Capacity and Behaviour of Geopolymer Concrete Beams Reinforced with Glass Fibre-Reinforced Polymer Bars

Abstract

AbstractGeopolymer concrete (GPC) with Glass fibre-reinforced polymer (GFRP) bars can provide a better construction system with high sustainability, high durability, and adequate strength. Few studies deal with the combination of these materials. The present investigation obtains the flexural capacity and behaviour of GPC and ordinary Portland concrete beams reinforced with GFRP bars (GFRP-RGPC and GFRP-ROPC, respectively). Twelve beams consisting of nine GFRP-RGPC and three GFRP-ROPC beams were cast and tested by using the four-point bending test over an active span of 2000 mm. Rebar ratio, compressive strength, and concrete types were taken as the variables. Initial cracking load, ultimate load capacity, load–deflection behaviour, Load–strain curves, crack width, the number of cracks and failure modes, were studied. Experimental results of beams were compared with the proposed equations provided by ACI 440.1R-15, CSA S806-12, and parabolic stress block method. The Results showed the decrease of deflection and increase of first cracking load by increasing the compressive strength. A slight increase in the deflection of GFRP-RGPC beams and approximately the same value of ultimate load were observed. GFRP-RGPC beams also recorded a higher value of crack width compared with GFRP-ROPC beams. The parabolic stress block method predicted the flexural capacity of the beams close to the experimental results rather than ACI 440.1R-15 and CSA S806-12.