Behavior of RC deep beams strengthened with different strengthening configurations of NSM GFRP bars

The purpose of this research is to conduct an experimental examination of the behavior and failure of deep reinforced concrete (RC) beams reinforced with near surface mounted (NSM) glass fiber reinforced polymer (GFRP) bars. In the experimental testing, ten RC deep beams with cross-sectional measurements of (400160) mm and a total length of (1500) mm were used. The beams were strengthened with NSM GFRP bars in a variety of strengthening configurations, with one beam specimen left unstrengthened as a control. Two loading points were applied to all RC deep beams until failure at various shear spans and effective depth ratios (a/d). The effects of GFRP bar diameters, spacing, and inclinations on the performance of reinforced deep beams were investigated and addressed. The test results revealed that the ultimate strength of strengthened beams increased significantly. Furthermore, more specialized strengthening techniques increased ductility while decreasing diagonal crack width.