Behavior of Damaged Continuous Reinforced Concrete Beams Repaired by CFRP Sheets

Abstract

Despite the widespread use of RC continuous beams, the performance of these beams, when repaired via Fiber Reinforced Polymer (FRP) composite material, has received less attention. Furthermore, several features of the flexural aspect of repaired RC continuous beams still demand experimental and analytical evaluation. However, many anchoring methods have been developed to delay premature failure in the RC beams, which are strengthened with FRP composite materials. The plan of this experimental study consists of eight continuous beams cast with dimensions (150*250*2800) mm considering the length of the clear span is 1300mm. Except for one, all specimens were attached via Carbon FRP sheets about 70% of the span length in negative and positive moment zones beyond a predetermined damage level. Moreover, this study suggested modifying the end-anchor technique and adding CFRP layers with (45, 65, and 95) % as damage ratios. According to the results, the optimal percentage of restored ultimate capacity was 108.8% with peeling-off concrete cover failure mode, which was obtained from using an end-anchor and two layers of the sheet. Also, increasing the damage ratio leads to a decline in toughness and ductility values. In addition, it is possible to repair the structure with a 95% damage ratio rather than remove it.