Experimental Study on RC T-Section Beams Strengthened with Bottom Steel Plates

Steel plates have become among the most popular means for strengthening or repairing of concrete structures, especially in strengthening flexural members. Considerable research has been conducted to investigate the static behavior of reinforced concrete (RC) beams strengthened with externally bonded steel plates. However, comparative studies on the bonding efficiency of this strengthening technique are still limited. In this paper, 8 specimens with five specimens strengthened with externally bonded steel plates were prepared and corresponding quasi-static tests were carried out to investigate their flexural behavior. Failure mode, cracking resistance and yielding and ultimate resistances of RC T-section beams strengthened by steel plates were reported. The influences of U-wrap spacing, flexural reinforcing ratio and strength of concrete on flexural behavior of the strengthened beams were analyzed and discussed. U-wraps made of steel plates and cohesive materials can work synergistically, which can effectively prevent debonding failure of steel plates. All test specimens failed in flexural bending. The influences on the structural behavior of RC T-section beams were compared and analyzed. Analytical models were also developed to predict cracking resistance, yielding and ultimate resistances of RC T-section beams strengthened by steel plates that failed in flexural bending. The accuracy of the developed analytical models was validated through comparing the predictions by these models with those reported by test data for the 8 specimens.