| Reinforced concrete(RC)structure composed of concrete and reinforcing steel,has been the most widely used structural system all over the world.To investigate the interactive mechanism between the two materials,this paper conducted a component-based analysis on the bond-slip relationship between concrete the reinforcing steel and its impact on the overall performance and local response of the component.The research contents included in this paper are as follows:(1)The separation finite element numerical model was established to analyze the effect of bond slip on the mechanical properties of the drawing members and the bending members.Firstly,the pull-out members are analyzed by using the three-dimensional separate modeling method in OpenSees program.The bond-slip state between concrete and reinforcing steel at each incremental step are studied,and the influence of mesh sizes on calculating results are analyzed.The three-dimensional separate finite element numerical model of the flexural member is established to study the constitutive relationship of bond slip under uniaxial loading and the effect of bond slip on the bearing capacity of the beam.The distribution of bond-slip between concrete and reinforcing steel along the beams are analyzed to investigate the easily-induced position of bond slip,and to compare the influence of different parameters including the corrosion of steel bars on the bond slip curve.The numerical analysis results of beam members revealed that bond-slip will to some extent influence the bearing capacity of RC members even at small slip magnitude.(2)The finite element numerical models of various column members are established.Based on the column members,the advantages and disadvantages of three modeling methods are compared,including the three-dimensional separate numerical modeling method,the fiber model method considering strain permeation of reinforcing steel and two-dimensional plane stress numerical simulation method.In the numerical models,the columns are cyclic-reversed loaded to investigate the constitutive relationship of bond-slip.In the analyses the effect of reinforcing steel corrosion are considered.The reduction of the reinforcement area,the yield strength of reinforcing steel and the bond stress between the reinforcement and the concrete are considered to establish the numerical model of different columns and to study the variation of bond-slip relationship.The research indicated that he decisive effect of the cross-sectional area and the yield strength of the steel bar under the low corrosion rate is the decisive effect on the bearing capacity of the column members,and the bond-slip relationship becomes an important factor to determine the bearing capacity of the column members,that is,the effect of bond slip is increased with the increase of corrosion rate.(3)Analyze the effect of bond-slip on the performance of shear wall members.Based on the previous analysis,two-dimensional cross-bar model and one-dimensional fiber model are used to analyze the shear wall members.The shear columns on both sides of the shear wall are modeled by fiber model,and the zero-length element is considered at the column restraint.The results show that the initial stiffness,the pinching effect and the reverse load bearing capacity of the shear wall hysteresis curve are closer to the experimental results after considering the effect of the strained stress on the shear wall.When the longitudinal reinforcement of the shear wall,The bearing capacity of the shear wall decreases with the increase of the corrosion rate. |
PDF Full Text Request