Repair of reinforced concrete deep beams using post-tensioned CFRP rods

A repair method for reinforced concrete deep beams with external unbonded post-tensioned carbon fiber reinforced polymer (CFRP) rods is presented. Reinforced concrete deep beams in this research were pre-damaged to simulate reinforced concrete girder webs with diagonal cracks. Experimental data and analytical methods for predicting the ultimate capacity of reinforced concrete deep beams which include the effect of externally post-tensioned CFRP rods are examined. The ultimate load capacity of the repaired beams was increased compared to the nominal capacity of the control beam while the deflection capacity remained the same. Strut-and-tie models of the control and repaired reinforced concrete deep beams predicted the ultimate load capacity with reasonable accuracy. The strut-and-tie models were optimized to reduce the ratio of experimental to analytical ultimate load capacity.