Abstract
The strengthening reinforcement is glued to the soffit of the reinforced concrete (RC) beams in the mainstream externally bonded reinforcement (EBR) technique for flexural strengthening. However, the soffit of RC beams could be inaccessible for strengthening due to limited or no space at the soffit because of walls or doors, or the spalling of concrete. To overcome such difficulties, this paper investigates the feasibility of the flexural strengthening of lightweight non-pre-cracked and pre-cracked reinforced concrete (RC) beams using the side externally bonded reinforcement (S-EBR) technique with carbon fiber reinforced polymer (CFRP) fabric. A total of eight full-sized RC specimens were fabricated, strengthened, and tested under four-point loading until failure. The test variables were the internal reinforcement ratio, percentage of pre-cracking loads, and the effect of cracking loads on the flexural performance. The loads, deflection, and ultimate failure of the specimens were recorded and the types of modes of failure were also observed. The S-EBR strengthening technique with CFRP fabric significantly enhanced the flexural capacity of non-pre-cracked and pre-cracked lightweight RC beams compared to the control specimen. An analytical model in accordance with ACI 440.2R-08 was developed to verify the experimental results. The flexural capacity predicted by the model was in reasonable agreement with the experimental results.