【摘要】 因受到氯离子侵蚀影响，海洋环境下钢筋混凝土（RC）建筑和基础设施结构长期性能会产生严重退化。为避免结构重建给生态环境带来更大的风险，同时考虑结构的耐久性、适用性和安全性，以及考虑成本效益和生态环境，需要对其进行大量修复与养护工作。为优化海洋环境下RC结构可持续维养方案，基于COMSOL软件，结合氯离子传输质量守恒方程，构建了海洋环境下维养后混凝土结构氯离子扩散多场耦合二维模型，并以钢筋初始锈蚀氯离子浓度阈值为控制标准，分析混凝土保护层更换修复、混凝土表面硅烷保护剂喷涂养护及其二者组合等三类维养策略和维养时间对维养后RC结构氯离子重分布和服役寿命延伸的影响。在此基础上，从维养策略可持续发展的角度出发，在平衡维养效果与维养成本、CO2排放和混凝土废弃物产生等方面，比较各维养策略优劣，并采用VIKOR多决策目标优化方法，确定最佳维养策略，最终构建了实现可持续维养管理的基本架构。研究结果表明：RC结构柱截面角部区域是评估氯离子浓度重分布并预测钢筋初始锈蚀和维养时间的关键部位；同时，针对不同可持续维养策略，混凝土更换与混凝土硅烷保护剂组合方案最优，所需的维养成本最低，对环境造成的负面影响最小。更多还原

【Abstract】 Chloride ion corrosion severely degrades the long-term structural performance of reinforced concrete(RC) buildings and infrastructures in marine environment. In consideration of the durability, serviceability and safety of the structures, as well as cost effectiveness and ecological environment, significant repair is required to avoid the major ecological risks associated with structural reconstruction. In this paper, a multi-field coupled two-dimensional model of chloride ion diffusion in repaired concrete structures under marine environment was constructed in the COMSOL software based on the partial differential equation of mass transport of dilute matter. Taking the threshold of chloride ion concentration at corrosion initiation of steel bars as a control standard, the effects of three repair strategies(viz concrete replacement, concrete surface spraying with silane sealer and combination of the two) and repair time on the redistribution of chloride ions and the extension of service life of repaired RC structures were analyzed. Furthermore, from the perspective of sustainable repair strategies, the advantages and disadvantages for each repair strategy were discussed in terms of the repair effect, repair cost, CO2 emissions and concrete waste generation. Finally, the VIKOR multi-decision target optimization method was used to determine the best repair strategy, and a basic framework for sustainable maintenance management was established. The results showed that the corner areas on cross-section of square RC structural columns were the key position for assessing the redistribution of chloride ion concentration and predicting the steel bar corrosion initiation and the repair time. For sustainable maintenance management strategies, the combination of concrete replacement with concrete surface sprayed with sealer wis the best one, having the lowest maintenance cost and the minimum negative impact on the environment. The results of the present study can provide a theoretical reference for relevant stakeholders to optimize the design and decision-making of sustainable maintenance management schemes for RC structures in marine environment.更多还原