PERFORMANCE OF CFRP SPLICES IN STRENGTHENING OF RC BEAM WITH WEB OPENINGS IN THE SHEAR REGION

摘要

The urgent need for an opening in the reinforced concrete (RC) beams after the construction for essential services causes local cracking around the opening which leads to decrease in stiffness and load carrying capacity. Therefore, strengthening the vicinity of the opening is essential to restore the loss in load carrying capacity of RC beam with cut-out web opening. In this study, Carbon Fibre Reinforced Polymer (CFRP) has been used for strengthening the opening region to substitute the loss of transverse steel reinforcement (stirrups) in the opening area for such cases. Two parameters have been investigated: the web opening's size and the number of the CFRP layers. Fourteen RC beams which comprises of solid beam, beam with small opening and three groups of beams with relatively large web opening in the shear region have been tested. Each group contains four beams with same web opening's size. In each group, one RC beam has been tested without CFRP strengthening, while the other three beams with different layers of CFRP strengthening (one, two and three layers). The results presented in this paper suggested that the losing in the load carrying capacity of the RC beam due to the cut-out web opening could be fully recovered by using multiple CFRP layers. In addition, the modified Eurocode 2 model (for CFRP strengthening of solid beam) can be used in predicting the shear force of RC beam with web opening in the shear region strengthened by multiple layers of CFRP.