坑蚀对钢筋混凝土梁抗弯承载力的影响

Influence of pitting corrosion on the bending capacity of reinforced concrete beams

比较了均匀锈蚀和坑蚀对锈蚀钢筋混凝土梁抗弯承载力的影响,定义了描述钢筋均匀锈蚀和坑蚀的两种参数。用试验数据比较了两种参数和锈蚀钢筋混凝土梁剩余抗弯承载力的关系,指出仅仅用均匀锈蚀描述锈蚀钢筋混凝土梁的抗弯承载力是不够的,还应考虑坑蚀的影响。研究了不同坑蚀系数下均匀锈蚀率和坑蚀锈蚀率的关系,指出确定钢筋坑蚀量的关键在于确定坑蚀系数的值,对坑蚀系数的选取应当慎重。给出了同时考虑协同工作系数和坑蚀系数的锈蚀钢筋混凝土梁抗弯承载力的计算公式,公式的计算结果与14根梁的试验结果可以很好吻合,表明所提出的公式可用于既有混凝土梁剩余抗弯承载力的评估。

Influences of both uniform corrosion and pitting corrosion on the bending capacity of the RC beams are compared. Parameters which describe both uniform corrosion and pitting corrosion are defined. Relationships between the two kinds of corrosion parameters and residual capacity of the corroded RC beams are compared by experimental data. It has been pointed out that only using uniform corrosion to describe the flexural strength of the corrosion reinforced concrete beams is not enough, pitting corrosion should also be considered. For different pitting factors, relationships between the uniform corrosion rate and pitting corrosion rate are researched. It has been found out that the key factor for determining the corrosion rate is the value of the pitting factor, which should be used carefully. Formula for the calculation of the bending capacity of the RC beams is given, and both coefficient of concordance and pitting factor are considered. For the good accordant between the calculation results and 14 beams＇ experimental results, the proposed formula can be used for evaluating the bending capacity of the existing RC beams.