Experimental studies on Shear behaviour of reinforced Geopolymer concrete thin webbed T -beams with and without fibres

This paper describes the experimental studies on shear behaviour of reinforced Geopolymer Concrete (RGPC) thin webbed Tee beams. Since T -beams are susceptible to shear, thin webbed T-beams are taken up for the current study. Shear failures are very sudden and unexpected, a thorough knowledge of the different modes of shear failures and the mechanisms involved is necessary to prevent them. Not many investigations were reported on the shear behaviour of RGPC. In the present study shear reinforcement spacing (0, 120, 180 & 240mm) was the basic test parameters for the beam specimens. Steel fibres were used for one set of beams and the same was compared for beams without fibres. After a series of trial mixes on geopolymer concrete, the volume of steel fibres was fixed as 0.75. All the beams were provided with the same flexural and shear reinforcement and the beams were tested under two point loading with shear span to depth ratio of 1.9. This paper presents the details of the mix proportion of geopolymer concrete (GPC) mixes, preparation of RGPC beams, testing and evaluation of structural behavior with respect to cracking, service load, deflections at various stages and failure modes. Investigations on the shear behavior of the reinforced concrete beams showed that the failure mechanism can be transformed from brittle to ductile mode by addition of steel fibres.