| Corrosion of steel bar is always the main reason that affects durability of reinforced concrete structure.Applying stainless steel bar to concrete structure can effectively prevent corrosion of steel bar.The research on the bond property between duplex stainless steel reinforcement and concrete and the establishment of an accurate constitutive model can provide important theoretical support for the structural design of duplex stainless steel reinforcement concrete.Therefore,it is of great significance to study the bonding properties of stainless steel bars and concrete.In this thesis,a total of 23 groups of specimens were analyzed through the central drawing test,and the factors affecting the bonding properties of stainless steel bars and concrete were mainly studied as follows:(1)Pull-out test was conducted on 11 groups of ordinary concrete central drawing specimens to explore the influence of concrete strength,reinforcement type,relative anchorage length and relative protective layer thickness on their bonding properties.In this experiment,two failure modes of reinforcement pulling out failure and concrete splitting failure occurred.Central drawing tests were conducted on 12 groups of UHPC central drawing specimens to explore the effects of stirrup reinforcement ratio,reinforcement type,relative anchorage length and relative protective layer thickness on their bonding properties.In this test,three failure modes of steel bar pulling out failure,concrete splitting failure and steel bar pulling out failure occurred.(2)Based on the central drawing test results of stainless steel bars and ordinary concrete,the influence factors of four influencing factors on the bond performance of reinforced concrete were analyzed,and the test results were statistically regressed to obtain the calculation formula of the average bond stress of ribbed stainless steel bars and concrete with respect to the relative anchorage length,relative thickness of protective layer and concrete strength.Based on the central drawing test results of stainless steel and UHPC,the influence factors of four influencing factors on the bond property of reinforced concrete were analyzed,and the test results were statistically regression,and the formula of the average bond stress of UHPC and ribbed stainless steel bars with respect to the relative anchorage length,relative protective layer thickness,concrete strength and hoop ratio was obtained.The bond stress distribution of reinforcement anchorage section is obtained by the strain values at each point of anchorage section.The bond slip constitutive model of UHPC and biphasic stainless steel bars was established by analyzing the test results and combining with the test data.(3)Based on the reinforced concrete bond slip constitutive model in the specification,ABAQUS software was used to build nonlinear elastic connectors in batches to simulate the bond slip between reinforcement and concrete.The load displacement curve obtained was compared with the test results,and the parameters were extended and analyzed. |
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