Flexural behaviour of concrete beams strengthened with near surface mounted AFRP rods and externally bonded fabric

Abstract

Strengthening with fibre reinforced polymer (FRP) composites is a widely used method for retrofitting or increasing load bearing capacity of structural members. FRP reinforcement is available in different forms such as laminates, sheets, bars, strips, grids and prestressing tendons to serve a wide range of purposes. This research work focuses on the use of FRP bars as near surface mounted (NSM) reinforcement and Externally Bonded (EB) 2D fabric for strengthening of concrete structures. Out of six steel reinforced concrete beams, two beams were strengthened with near surface mounted AFRP bars; three beams were strengthened at bottom using Kevlar (Aramid) fabric and the remaining one as unstrengthened beam. All the beams were tested under monotonic static two point loading. Two different diameters of 5.5mm and 7.5mm AFRP rods were used as NSM rods. From the experimental results, the load deflection behaviour and load carrying capacity of strengthened and unstrengthened beams were investigated. The mode of failure and the pattern of cracks formed during testing were also observed and presented. The effectiveness of strengthening method based on strength and deflection was discussed in this paper.