模拟酸雨侵蚀环境下钢筋混凝土结构长期性能研究综述

为深化对酸雨侵蚀环境下钢筋混凝土结构长期性能演变机制的认识，论述了酸雨侵蚀作用下混凝土材料腐蚀机理、侵蚀模型和物理力学性能时变过程；分析了酸雨锈蚀钢筋的溶液腐蚀机理和大气动态冲刷机制，总结了锈蚀钢筋形貌表征与锈蚀率指标定量化研究成果，归纳了已有锈蚀钢筋力学性能退化模型和本构模型，概述了钢混界面黏结性能演变规律和黏结-滑移本构关系模型；梳理了梁、柱构件及结构静、动力学性能演变规律的室内试验结果、理论计算方法和数值仿真结果的最新研究进展与不足，并展望了未来的研究方向与重点。研究结果表明:酸雨腐蚀混凝土可归因于酸雨离子成分的交互作用，亟需适用性较强的理论模型以揭示腐蚀和扩散机制；室内加速试验揭示了酸雨侵蚀作用下混凝土物理力学性能时变规律，应完善室内加速试验制度，搭建耦合宏细观层次关键指标的混凝土损伤评价体系和预估模型；酸雨加速锈蚀钢筋试验多基于均匀锈蚀，钢筋腐蚀方法和形貌表征逐渐向不均匀锈蚀发展，应进一步发展高精度扫描技术，借助统计分析理论建立钢筋不均匀锈蚀特征参数，优化钢筋力学性能退化模型；通电锈蚀试验和拉拔试验演绎了钢混界面黏结性能演化规律，并建立了黏结-滑移本构关系，但忽略了实际钢筋混凝土结构的受力特点，且锈蚀过程显著区别于自然锈蚀，应考虑酸雨环境与材料特性复杂多变的特点，研究细微观钢混界面损伤行为，揭示酸雨环境、材料特性与黏结性能的内在关系；酸雨侵蚀钢筋混凝土结构时效性能研究多集中在试件层次，且采用腐蚀试验与承载力试验分阶段进行，忽略了荷载-环境的耦合作用，试验所设环境较为单一，试验制度与方法亦未统一，应对标实际工程，考虑实际结构承载和环境工况，搭建长期荷载-酸雨侵蚀耦合作用试验系统，探索荷载-环境-材料多场关联机制，完善理论计算方法与数值仿真手段，揭示结构长期性能演变过程，并推动现场暴露试验发展，量化室内-现场映射关系，指导工程实际。 

Review on long-term performance of reinforced concrete structures under simulated acid rain erosion environments

To deepen the understanding of the long-term performance evolution mechanism of reinforced concrete structures under acid rain erosion environments, the corrosion mechanism, erosion model, and time-varying process of physical and mechanical properties of concrete materials under the acid rain erosion action were discussed. The solution corrosion mechanism and atmospheric dynamic scouring mechanism of steel bars corroded by acid rains were analyzed. The research results of morphology characterization and corrosion rate index quantification of the corroded steel bars were summarized, and the existing mechanical property degradation model and constitutive model of corroded steel bars were concluded. The evolution law of bonding performance of steel-concrete interface and the bonding-slip constitutive relation model were reviewed. The latest research progress and shortcomings of the evolution law of static and dynamic mechanical properties of beams, column components, and structures were reviewed in terms of indoor test results, theoretical calculation methods, and numerical simulation results, and future research directions and priorities were predicted. Research results show that the corrosion of concrete by acid rains can be attributed to the interaction of acid rain ion components, and a theoretical model with strong applicability is urgently needed to reveal the corrosion and diffusion mechanisms. The indoor accelerated test reveals the time-varying law of physical and mechanical properties of concrete under the action of acid rain corrosion, and the indoor accelerated test system should be improved. The damage evaluation system and prediction model of concrete should be built by coupling the key indicators at the macro and micro levels. The accelerated corrosion test of steel bars by acid rains is mostly based on the uniform corrosion, and the corrosion method and morphology characterization of steel bars are gradually developing towards uneven corrosion. High-precision scanning technology should be further developed, and the statistical analysis theory should be used to establish the characteristic parameters of uneven corrosion of steel bars, to optimize the mechanical properties degradation model of steel bars. The electric corrosion and pull-out tests deduce the evolution law of bonding performance of the steel-concrete interface, and build the bonding-slip constitutive relationship. However, the mechanical characteristics of the actual reinforced concrete structures are ignored, and the corrosion process is significantly different from the natural corrosion. The complex and changeable characteristics of acid rain environments and material properties should be considered to study the damage behavior of the steel-concrete interface at the micro level and reveal the internal relationship among acid rain environments, material properties, and bonding performance. The research on the aging performance of reinforced concrete structures eroded by acid rains is mostly concentrated on the specimen level, and the corrosion test and bearing capacity test are carried out in stages. The coupling effect of the load-environment is neglected. The test environment is relatively simple, and the test system and method are not unified. The bearing and environmental conditions of the actual structures should be considered according to actual projects, and a long-term load-acid rain erosion coupling test system should be built. The multi-field correlation mechanism of load-environment-material should be explored, and the theoretical calculation and numerical simulation method should be improved, so as to reveal the long-term performance evolution process of the structure, promote the development of field exposure test, quantify the indoor and on-site mapping relationship, and guide the actual projects.