Study On Bonding-anchoring Performance Between Reinforcing Bars And Concrete Under Chloride Corrosion And Freeze-thaw Cycles

The durability of concrete structures is a very important and urgent problem.In the severe cold regions of the north of China,especially in the reinforced concrete structures of the sea and offshore areas,early freeze damage to the structure and loss of structural durability due to freeze-thaw damage to the concrete and corrosion of the concrete structure by the marine environment,especially corrosion of the steel bars,this has become an important issue for the failure of practical projects.Freeze-thaw and chloride ion corrosion will both destroy the bond between reinforcing steel and concrete,bonding is the basis for the joint work between steel and concrete,therefore,research on the coupling of chloride and salt corrosion and freeze-thaw cycles for reinforcement and concrete Bonding and anchoring properties are particularly important.In practical projects,the failure of most concrete structures is the result of a combination of various factors.Therefore,in this paper,through the center pull test method,the strength and bonding anchorage performance of reinforced concrete after freeze-thaw cycle and chloride salt corrosion coupling are discussed.In this experiment,three different freezing and thawing times(15 times,25 times,50 times)and three different concentrations(3.5%,7%,10%)of chlorine salt solution are set up for orthogonal test,mainly for the study of the following issues:(1)Experimental study on bond strength and bond slip of concrete specimens after freeze-thaw cycles and after freeze-thaw cycles and chloride corrosion.(2)Analysis the effect of freeze-thaw cycles and chloride corrosion on bond properties of concrete specimens.(3)Numerical simulation of light round bar,and compared with the test results.The results show that the bond strength of concrete specimens has decreased significantly trends with the increase in the number of freeze-thaw cycles;the effect of chloride on the bonding performance is related to the number of freeze-thaw cycles and the degree of corrosion.