| For the widely used reinforced concrete structure,the failure of the bond between the reinforcing steel and concrete results in serious safety hazards.Among them,the corrosion of the reinforcing steel is the main factor for the deterioration of the bond between the reinforcing steel and concrete.In addition,the bonding performance of reinforcing steel and concrete is also affected by the nature of the material itself,the structural stress state,the shape of the contact surface between reinforcing steel and concrete,concrete carbonation and other factors.When the bridge is subjected to seismic load,the pier,which is prone to reinforcement corrosion in reality,will also be subjected to complex loading.And the complex force will destroy the bond between the reinforcing steel and concrete in certain locations of the pier,which will lead to the overall failure of the structure.Therefore,there is an urgent need to investigate the bonding properties of rusted reinforcing steel and concrete and their effects on the earthquake-resistance performance of bridge piers.This paper is mainly about the following contents.(1)Combined with the advantages of the previous bonding test,a half-beam bonding test was designed,and two sets of half-beam specimens were prepared for hoop closure and hoop non-closure.And after accelerated rusting of the specimens by electrification,rusted reinforcing steel and concrete bonding specimens were obtained.After the bond test was loaded,there was a large difference in the bond damage test phenomenon between the two groups of specimens,while data on the bonding performance of rusted reinforcement to concrete was collected.(2)In order to explore the degradation law of bonding performance of reinforced concrete under rusting conditions,data software was applied to statistically analyze the bond strength,bonding slip and other data obtained from the test to derive the degradation law of bonding performance of reinforced concrete.(3)Finite element modeling analysis was performed for the half-beam bond test,and the bonding of reinforced concrete was simulated by applying the cohesive force model,and the experimental results were compared with the computed results to verify the feasibility of the modeling method.References were provided for modeling the bond of rusted reinforced concrete by using the finite element software ABAQUS.The bond failure of reinforcing steel to concrete is not only affected by the reinforcement slip,but also by the bending of the specimen beam.During the test loading process,the distribution of stress values on the surface of the reinforcement in the bonded section of the half-beam specimen showed complex changes during the bond failure of the reinforcing steel to concrete.(4)By applying the modeling method given in the paper for the bonding of reinforcing steel and concrete,the seismic performance of a rusted reinforced concrete bridge pier with seismic test data was numerically simulated,and the computed seismic performance of the bridge pier with bonding slip taken into account showed better credibility.An analysis of the influence of the degradation of the bonding properties of reinforcing steel and concrete on the seismic performance of bridge piers showed that the more serious the degradation of the bonding properties of reinforcing steel and concrete,the faster the bearing capacity of bridge piers decreases when subjected to seismic loading.The research results of this paper can contribute to the correct solution of the problems arising from the corrosion of reinforcing steel in engineering structures,and also provide useful references on the evolution of seismic performance of bridges in coastal areas. |
