Abstract:
Epoxy resin in near-surface-mounted (NSM) carbon fiber reinforced polymer (CFRP) reinforced concrete structure has a certain temperature sensitivity. The properties of epoxy resin and its bond behavior in the reinforced structure were experimentally studied at different curing temperatures and ambient temperatures. The results show that: (1) The curing time of epoxy resin is greatly shortened with the increase of curing temperature, and has little effect on its tensile strength and shear strength, the tensile strength only decreases slightly by about 10% when curing temperature exceeds 80℃. But the tensile strength and shear strength of epoxy resin decrease obviously with the increase of ambient temperature. Epoxy resins with higher curing temperatures have more stable shear properties at 60℃ or higher ambient temperatures; (2) The effect of curing temperature on the CFRP-concrete interface bond property of NSM CFRP reinforced components is small, but the interfacial bond behavior decreases with the increase of ambient temperature, and the maximum reduction is about 58.89%. The failure mode also changes from concrete cohesive failure to epoxy resin-concrete interface failure and CFRP-epoxy interface failure. The specimen with higher curing temperature shows higher bonding strength at high ambient temperature. In addition, the bond-slip curves of the specimen interface are fitted on the basis of the test, and the relationship between the characteristic parameters of the curve and the ambient temperature is established.