锈蚀钢筋混凝土梁抗弯承载力计算方法

Calculation method for flexural capacity of corroded RC beams reinforced concrete beams

基于锈蚀钢筋混凝土梁内钢筋与混凝土间黏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。当钢筋锈蚀量较小时,锈蚀梁内钢筋与混凝土间黏结强度随锈蚀量变化不大,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;但随着钢筋锈蚀量的增加,钢筋与混凝土间黏结强度发生退化,锈蚀梁的力学性能介于黏结完好梁与无黏结梁之间,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,提出概念明确、通用性强的锈蚀钢筋混凝土梁抗弯承载力计算方法;经试验验证,数据吻合很好,其结果有益于完善和发展锈蚀钢筋混凝土梁抗弯承载力的计算方法。

Flexural carrying capacity of corroded reinforced concrete 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 doesn＇t have great changes with increasing degrees of corrosion,the mechanical behavior of the corroded RC beams is the same as that of the non-corroded 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 pa-per,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 forwhole beams,a calculation method for flexural capacity,conceptually explicit and widely applicable,was pro-posed,taking consideration of both corrosion degree and reinforcement index.The results were useful to perfect the calculation method of the flex-ural bearing capacity of corroded reinforced concrete beams.