Repairing of damaged reinforced concrete beams using ultra-high-performance fiber reinforced concrete

Abstract

Reinforced concrete (RC) structures have a life span of about 50 to 60 years. Over the last few years most RC structures especially in Lebanon are reaching the end of their lifetime. The propagation of macro-cracks can be seen in deteriorated RC structures and therefore repair is needed. Previous studies show that the use of ultra-high performance fiber reinforced concrete (UHPFRC) improves the structural resistance of RC buildings and extends its durability. In this research, experiments were done on full-scaled RC beams fully damaged by exceeding the yield stress of the reinforcing steel bars and where major cracks appear along the beam due to large applied loads. Three beams, two with recycled aggregates and one with normal aggregates were re-tested after repairing them with UHPFRC. A finite element model was done using ABAQUS to compare experimental and analytical results. The investigation shows improvement in the structural behavior of the RC beam after applying UHPFRC. Recommendations are finally made for future repairing of damaged concrete beams using UHPFRC.