基于锈胀裂缝宽度的损伤混凝土梁可靠度分析

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中图分类号：TU375.1 文献标志码：A 文章编号：2096-6717（2025）04-0140-08

Reliability analysis of damaged concrete beams based on the rust crack width

BAI Yuliang，JIN Weiliang，YU Yifan，JIN Kangcheng （College of Civil Engineering and Architecture， Zhejiang University，Hangzhou 3lOo58，P.R.China）

Abstract： In order to investigate the degradation law of the durability of damaged concrete beams，by introducing the fatigue damage factor and the creep damage factor，the calculation model of the corrosion depth of the steel bar after corrosion cracking of the protective layer of the concrete beam with fatigue and creep damage was established.According to the durability design standard of concrete structure，the durability limit state equation controlld by the rust crack width was established.The Monte-Carlo numerical simulation method was used to calculate the reliability of six concrete test beams within the crack width limit.The sensitivity of the four parameters，including corrosion current density，concrete compressive strength，protective layer thickness and stee bar diameter，was calculated using the checkpoint method.The research results show thatthe reliability decreases from O.9 toO.1 with the increase of corrosion time and the increase of holding time for three months has little efect on the reliability of the beam after cyclic loading of 60% of the fatigue life times.

The increase of the protective layer thickness and the decrease of the diameterof the steel bar canboth improve thereliability of the beam and slow down the decline rate of the structural reliability at the early stage of corrosion of the steel bar. The steel bar diameter of 8mm can be used as a reference value for the durability design of damaged concrete beams. The sensitivity of the three parameters of corosion current density， protective layer thickness andsteel bar diameter is so relatively large that three parameters are the main influencing factors of durability limit state reliability.

Keywords： damaged concrete beams; rust crack width; limit state equation; reliability; sensitivity

在钢筋混凝土结构服役期间，环境中的有害介质侵入混凝土内部，导致钢筋表面的钝化膜破坏，引起钢筋的锈蚀。（剩余12486字）