Shear strengthening of polystyrene aggregate concrete beams with near surface mounted GFRP bars

The application of near surface mounted (NSM) fibre reinforced polymer (FRP) bars is emerging as an innovative and promising technology for increasing flexural and shear strength of deficient reinforced concrete members. In order for this technique to perform effectively, a series of experimental works have been carried out to characterise the flexural and shear behaviour of reinforced concrete members strengthened with NSM FRP bars. The latter is the focus of this paper, and some of the preliminary results are included. A total of eight beams were loaded under a two-point symmetrical bending test. The parameters examined were the type and inclination of NSM bars and the type of adhesives employed. Characterisation of the tested beams, including mode of failure and load-deflection response, is presented and discussed in this paper. The results of this investigation showed that the NSM bonded glass FRP bars can be used to significantly increase both shear and flexural stiffness and the ultimate moment capacity of the beams, with an efficiency that varies depending on the tested variables. © W. S. Maney & Son Ltd. 2010.