Journal of Adhesion Science and Technology, Vol.31, No.21, 2360-2379, 2017
Repair technique of pre-cracked reinforced concrete (RC) beams with transverse openings strengthened with steel plate under sustained load
This paper presents a repairing technique of the steel plate that effectively strengthen RC members, control both the failure modes and the stress distribution around the beam chords and enhance the serviceability of pre-cracked RC beams with openings. Furthermore, to evaluate the usage of a temporary pre-stressed force that was applied on the RC beam so as to close all of the presence shear cracks before the steel plate application. Two un-strengthened control beams, five beams that were pre-cracked before the application of the steel plate, and one beam that was strengthened without pre-cracking were tested. Cracking was first induced, followed by repair using various strengthening technique, and then the beams were tested to failure. The advantages of the shear strengthening of RC beams that were obtained using this technique are based on the closing of all the existing cracks around the openings via epoxy injection. The results show that both the pre-existing damage level and the steel plate strengthening have a significant effect on strengthening effectiveness and failure mode at the ultimate strength. An analytical equation for predicting the shear strength of pre-damaged RC beams with circular openings was then proposed, and the obtained results later compared with those from the tests, results were in accordance.