基于粘结强度变化的锈蚀钢筋混凝土梁受弯承载力的研究

基于锈蚀钢筋混凝土梁内钢筋与混凝土间粘结强度随锈蚀量的变化，对锈蚀梁的抗弯承载力进行了研究。钢筋锈蚀量较小时，锈蚀梁内钢筋与混凝土间粘结强度随锈蚀量增加而增加，锈蚀梁的力学性能同未锈蚀梁，可运用传统的梁理论计算锈蚀梁的抗弯承载力；随着钢筋锈蚀量的增加，钢筋与混凝土间粘结强度发生退化，锈蚀梁的力学性能介于粘结完好梁与无粘结梁之间，与传统的计算梁的抗弯承载力的方法不同，应考虑梁的各截面间相互作用。基于梁整体的受力平衡和变形协调，建立了考虑梁内粘结强度退化的锈蚀梁抗弯承载力模型。最后，通过54根锈蚀梁承载力试验结果，对文中建立的模型进行了验证分析，结果十分满意。

Research on the flexural carrying capacity of corroded RC beams on the basis of the change of bond strength

Flexural carrying capacity of corroded reinforced concrete(RC) beams is modeled and calculated on the basis of the change of bond strength between corroded steel and concrete.At lower degrees of corrosion level,bond strength between steel and concrete(increases) with increasing degrees of corrosion,the mechanical behavior of the corroded RC beams is the same as that of the noncorroded ones,flexural carrying capacity of corroded RC beams can be calculated by conventional theory of the beam.When reduction of bond strength occurs due to higher degrees of corrosion,the mechanical behavior of the corroded RC beams lies in between that of the(perfectly) bonded and unbonded beam.It is different from the traditional way in RC beams,the interaction between cross sections of beams should be considered.In the present paper,the change of bond strength between corroded steel and concrete is considered,and on the basis of the condition of equilibrium of forces and compatibility of deformations for whole beams,a model for the prediction of flexural carrying capacity of the corroded RC beams is proposed.Comparison between the calculated results and the corresponding test results shows it is very satisfactory.