Shear strengthening of normal steel reinforced concrete beams using post-tensioned metal straps fully wrapped around the beams

Abstract

Using post-tensioned metal straps (PTMS) as a method of strengthening reinforced concrete building members is relatively new, however, it has been tested mostly on small specimens. Therefore, this study is an attempt to show the effectiveness of PTMS fully wrapped around medium- scale steel reinforced concrete (RC) beams to enhance their shear strength. For this purpose, four normal RC beams are constructed without transverse reinforcement with dimensions of 160 mm × 240 mm x 1050 mm which are width, depth, and length respectively. To strengthen the beams, PTMS is wrapped fully around the beams at different locations with different strip numbers. It is found that if used properly, PTMS can effectively alter the type of failure of the beams from a brittle shear failure to a ductile bending failure. Additionally, the load-carrying capacity of the beam can increase by 143%, 170%, and 182% by using two, four, and six strips of PTMS respectively. Moreover, the deflection capacity increases by 643%, 557%, and 653% by using two, four, and six straps of PTMS. Finally, after using PTMS on the beam there is a reduction in the number of cracks and the location of their appearance will be localized in the center of the beam.