氯离子侵蚀下钢筋混凝土非线性锈胀破坏过程模拟

Simulation of Nonlinear Corrosion Damage Process in Reinforced Concrete under Chloride Environment

钢筋锈胀破坏会显著改变氯离子在混凝土中的输运通道,氯离子侵入与锈胀致裂是相互加强的非线性过程.围绕这一非线性破坏过程开展了数值模拟方法研究,建立了氯离子扩散与钢筋锈胀破坏间的耦合分析方法,并基于商业软件ABAQUS平台,通过二次开发,高效地实现了这一非线性模拟过程.利用文献中的试验数据,验证了所建立方法的有效性.模拟结果表明:是否考虑氯离子扩散与锈胀损伤破坏间的耦合过程,对钢筋混凝土结构使用状态的评估结果影响显著,且耦合分析预测结果更为精确.

Corrosion of rebar significantly affects the transfer path of chloride ions in concrete, and the penetration of chloride ions as well as the erosion of rebar in concrete are two nonlinear mutually strength- ening and coupling processes. This paper proposed numerical methodologies to solve the nonlinear prob- lem. An efficient iterative algorithm was established for simultaneously analyzing the penetrating process of chloride ions into concrete and the evolution of concrete damage, and was subsequently implemented and integrated into ABAQUS with user subroutine. Efficiency and reliability of the proposed method was certi- fied with the test data from literatures. Numerical results clearly demonstrated that the coupling process between chloride ions penetration and concrete damage evolution greatly affected the assessment of the in- tegrity of reinforced concrete structures. The developed method could give more comprehensive evaluation of the service life of reinforced concrete structure, and provide new guidelines for the durability analysis of concrete structures under marine environment.