Research On Moisture And Heat Resistance Of Underwater Curable Adhesive And Its Bonding With Steel

Carbon fiber reinforced resin composite material(CFRP)cementation reinforcement repair technology,due to its advantages of high operational safety and convenient construction,is widely used in the reinforcement and reinforcement of steel structures.Humid and hot environments can easily cause damage to civil engineering materials and structures.Therefore,strengthening and repairing damaged structures in the above-mentioned service environment has become an important research direction in this field.Epoxy resin adhesives cannot be cured in a water environment.In order to solve this problem,this paper developed a resin system that can be cured quickly in water environment,and studied the thermal and mechanical properties of adhesives and the long-term evolution of the bonding properties of the adhesive with steel in hot and humid environments.The main research content and achievements of the thesis are as follows:The underwater curing behavior of high-viscosity structural adhesives and low-viscosity dipping adhesives and the effect of underwater curing on the thermal and mechanical properties of the two adhesives are studied.Research shows that both adhesives can be cured in water environment and the best curing time is 5 days;the tensile strength of structural adhesive and impregnated adhesive cured in water environment are 44.3MPa and 46.5MPa.The water absorption behavior and mechanical properties of high-viscosity structural glue and low-viscosity dipping glue under water immersion were studied.Studies have shown that the saturated water absorption rates of structural adhesives and impregnated adhesives reach 2.1% and 1.7%,respectively;the tensile strengths of structural adhesives and impregnated adhesives are significantly degraded under distilled water environment;after 100 days of immersion in water environment,the tensile strength of structural adhesives cured in water environment The retention rate of tensile strength is 40.1%(20℃),46.4%(40℃)and 53.3%(60℃).The retention rate of tensile strength of the impregnating rubber cured in water environment is 72.5%(20℃),77.8%(40℃)and 86.4%(60℃).The interfacial bonding properties of high-viscosity structural adhesives,low-viscosity dipping adhesives and steel under water immersion were studied.Studies have shown that the bonding strength of the structural adhesive,impregnated adhesive and steel interface cured under water is reduced by 56.2% and 60.5% respectively compared with the dry curing environment;after 75 days of immersion in the water environment,the water environment cured structural adhesive is reduced by 10.14MPa(initial Value)is reduced to 3.86 MPa(20℃),4.60 MPa(40℃)and 6.52 MPa(60℃),the water environment curing impregnating glue is reduced from 6.27 MPa(initial value)to 2.82 MPa(20℃),3.47 MPa(40℃)and 4.46MPa(60℃).