Experimental investigation on mechanical performance of carbon fiber reinforced polymer wire after exposure to elevated temperature

The current study experimentally investigated the influence of elevated-temperature exposure on the mechanical performance of carbon fiber reinforced polymer (CFRP) wires through conducting the axial tensile, threepoint bending and transverse load tests. The results show that the CFRP wires under axial tensile load exhibited a brittle fracture after exposure to 30 and 100 degrees C, and the wires after 200 degrees C exposure were pulled out from the anchorage. The axial tensile and three-point bending performance of the wires were adversely affected by the elevated temperature; and with the increase of the exposed temperature, the maximum contact force, maximum wire tension, maximum wire tension increment, deflection at fracture and the energy dissipation capacity of the preloaded CFRP wires in the transverse load tests declined. Based on the experimental results, reduction functions were established to quantify the degradation in tensile properties of the CFRP wires after elevatedtemperature exposure, and the formulas used for predicting the post-elevated temperature transverse failure responses of the preloaded CFRP wires were proposed. Furthermore, through verification by the test results, the previously established failure criteria are demonstrated to be applicable to assess the failure state of a CFRP wire after evaluated-temperature exposure when subjected to combined tension and bending.