Fracture Characteristics of FRP Reinforced Precast Cracked Concrete

In order to study the fracture characteristics of fiber reinforced polymer(FRP) reinforced precast cracked concrete and obtain the best reinforcement effect of single layer FRP on concrete with different crack-depth ratio, the fracture tests of FRP reinforced precast cracked concrete three-point bending beams with the same size and different initial crack-depth ratios(0.2, 0.3, 0.4, 0.5) were carried out. Based on FRP-concrete interface bond slip model, the fracture parameters of FRP reinforced precast cracked concrete three-point bending beams were obtained. The conclusions can be drawn that, the peak load of FRP reinforced precast cracked concrete from the load-crack mouth opening displacement(P-CMOD) curve is much higher than that of ordinary concrete, and the peak load of FRP reinforced precast cracked concrete increases first and then decreases with the increase of crack-depth ratio. In the range of crack-depth ratio from 0.2 to 0.5, the initial crack toughness of FRP reinforced precast cracked concrete can be considered as a constant. The instability toughness of FRP reinforced precast cracked concrete increases first and then decreases with the increase of crack-depth ratio. When the crack-depth ratio is 0.4, the instability toughness reaches the maximum, which indicates that the reinforcement effect is the best. Compared with the brittle fracture failure of ordinary concrete under instability load, the ductility of FRP reinforced precast cracked concrete during fracture failure process is significantly improved. © 2020, Editorial Department of Journal of Building Materials. All right reserved.