本文将锈蚀钢筋混凝土梁视为由锈蚀钢筋和混凝土组成的存在粘结滑移的组合梁,以锈蚀钢筋与混凝土之间的变形协调条件为依据,引入反映锈蚀钢筋混凝土力学性能的本构关系和锈蚀钢筋与混凝土之间的粘结.滑移本构关系,推导出以纵向受拉钢筋拉力N表达的锈蚀钢筋混凝土梁非线性微分方程。通过求解该微分方程,给出了考虑粘结滑移的锈蚀钢筋混凝土梁非线性解析解,以该解析解为基础,给出了以锈蚀钢筋混凝土梁特征值λ表达的截面协同工作系数理论表达式。通过该截面协同工作系数,建立了能准确反映粘结滑移的锈蚀钢筋混凝土梁截面承载力与变形的非线性实用分析方法,使锈蚀钢筋粘结强度降低系数与截面协同工作系数之间得到了统一,解决了二者之间长期以来不协调的矛盾,编制了计算机程序,并与已有实验结果进行了对比,说明了该方法的准确性。
The corroded reinforced concrete beam is regarded as a composite beam which consists of corroded steel bars and concrete with bond-slip. According to the deformation compatibility relationship between coi'reded steel bars and concrete, on the basis of the constitutive relationship which can reflect the mechanical properties of corroded steel bars and concrete and the bond-slip constitutive law, a nonlinear differential equation for the beam, expressed in the form of the tensile force (N) of axial steel bars, is derived. A nonlinear analytical solution with considering the bond-slip of the beam is obtained by coefficient in the form of the characteristic value of the practical nonlinear analysis method which can exactly solving the differential equation, by which a coordination beam (λ) is deduced. Due to the coordination coefficient, a reflect the bearing capacity and deformation of the beam is established, by which the contradiction between the deterioration coefficient of bonding strength of corroded steel bar and the section coordination coefficient is eliminated. The effectiveness and accuracy of the practical analysis method is demonstrated by comparing its values computed by a program with the former validated experimental results.