Abstract: The mechanical behaviors of aramid and carbon fiber-reinforced polymer (AFRP and CFRP) sheets as well as a corresponding epoxy adhesive after 60,80,100,120 and 140 freeze-thaw cycles,were experimentally in- vestigated,and the freeze-thaw resistance of the AFRP sheet was compared with that of the CFRP sheet.Experi- mental results show that (1) in comparison with the CFRP sheet,the AFRP sheet after the freeze-thaw cycling has a greater change of tensile properties,and shows a worse freeze-thaw resistance; (2) after 140 freeze-thaw cycles,the tensile strength and elastic modulus of the AFRP sheet decrease respectively by 8. 2% and 14.0%,in com- parison with those of the control sheet exposed to ambient conditions; (3) however,the elastic modulus of the CFRP sheet after 140 freeze-thaw cycles is close to that of the control one,and the tensile strength of the CFRP sheet experiences a loss of 6.1% after 60 freeze-thaw cycles and then keeps almost constant or slightly increases; (4) the rupture elongations of the AFRP and CFRP sheets after freeze-thaw cycling are close to or slightly higher than those of the control ones,but the variaiton range of the elongation of the AFRP sheet is wider than that of the CFRP sheet; and (5) there is no decrease in the tensile lap-shear strength of the epoxy adhesive after 140 freeze- thaw cycles.

Key words: AFRP, CFRP, epoxy adhesive, freeze-thaw cycling, mechanical behavior