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和混凝土之间的黏结一滑移本构关系,推导出以纵向受拉钢筋拉力表达的锈蚀梁非线性微分方程。通过求解该微分方程,给出了考虑黏结滑移的锈蚀梁非线性解析解和截面协同工作系数理论表达式,使锈蚀钢筋黏结强度降低系数与截面协同工作系数之间得到了统一。文中还对影响截面协同工作系数的因素,即锈蚀量特征值、荷载作用形式及截面位置进行了讨论,并与试验归纳总结的截面协同工作系数进行了比较分析,说明了该理论表达式的合理性。
The corroded reinforced concrete beam is treated as a composite beam which consists of corroded steel bars and concrete. Based on the deformation compatibility relationship between corroded steel bars and concrete, the constitutive relationship synthesizing the mechanical properties of the corroded steel bar and concrete and the constitutive relationship of their bond-slip are established. A nonlinear differential equation is proposed which can express the tensile strength of the longitudinal steel bars of the corroded reinforced concrete beam. The equation could be analytically solved by inducing a section coordination coefficient characterizing bond-slip properties. Based on the solution, the contradiction between the deterioration coefficients of bonding strength of corroded steel bars and the section coordination coefficient is eliminated. Factors affecting the section coordination are revealed and discussed. Comparison of the section coordination coefficient with experimental results indicates the rationality of the theoretic formulation.