Flexural Behavior of Fire-Damaged Reinforced Concrete Slabs Repaired with Near-Surface Mounted (NSM) Carbon Fiber Reinforced Polymer (CFRP) Rods

After fire, the decrease in load capacity of reinforced concrete (RC) structure will take place and may lead to a damage. This research brings out a method to repair flexural reinforced concrete members after fire by using near-surface mounted (NSM) carbon fiber reinforced polymer (CFRP) rods. In this study, a series of slabs were conducted to evaluate the flexural behavior of fire-damaged RC structures strengthened with NSM CFRP rods and repairing material. The arrangement or the location of NSM CFRP rods were the main factor that had been considered to evaluate the effectiveness of this method. Besides, the direct bond test of C-shaped specimens was carried out to investigate the bond behavior between CFRP rods and concrete in three different embedding positions of CFRP rods. Based on the experimental databases, it is clear to conclude that the strengthened slabs not only improved endurance limits but also improved load-carrying capacities and stiffness values as compared to control slab and fire-damaged slab. Especially, the test results showed that slabs with CFRP rods embedded in repairing material overlay had more load-carrying capacity than slabs with CFRP rods embedded inside concrete or between concrete and repairing material overlay.