基于多孔骨料“微泵缓释”阻锈剂的全珊瑚海水混凝土钢筋锈蚀的基础研究

For the reef construction background of South China Sea, with the synergy between micro pump slow-release effect of corrosion inhibitor in coral aggregate and coated reinforcement, micro pump effect of porous coral is used and a new pretreatment methods of corrosion inhibitor pre-absorb and storage by coral aggregate is presented. That way, some theoretical and application-related problems of reinforcement corrosion in coral aggregate seawater concrete structure will be systematically solved. It has great theoretical significance, national defense significance and engineering application value to the improvement of the coral concrete structure’s carrying capacity protective capability. In the present project, it mainly studies the corrosion behaviors and critical chloride concentration of different kinds steel and coated steel which immersed in simulated pore solution. This project will explores the migration mechanism and mechanism of the micro pump slow-release of inhibitor in coral aggregate and the synergistic mechanism between chloride diffusion and corrosion inhibitor release. The electrochemical mechanism of repassivation behavior, passive film repair and reconstruction of pitting corrosion steel bar will be studied. Besides, based on the high frequency capacitance arc characterize of electrochemical impedance spectroscopy, a new equivalent electrical circuit model will be established to characterize the passive film or the adsorption film, and master the essentials of mechanism of steel bar corrosion in coral concrete accurately. This project will provide the basic theory of steel bar corrosion protection and technical method for the reinforced coral concrete structure, and drive the progress of science and technology of China's reefs coral concrete structure.

针对我国南海岛礁工程建设背景，提出采用多孔珊瑚“微泵”效应、预先吸收并储存阻锈剂的骨料预处理新方法，借助骨料“微泵缓释”阻锈剂及其与涂层钢筋的协同作用，系统解决全珊瑚海水混凝土结构钢筋锈蚀的应用基础理论问题，对于提高我国岛礁珊瑚混凝土结构的承载能力和防护能力，具有重要的理论意义、国防意义和工程应用价值。主要研究不同种类钢筋或涂层钢筋在该混凝土模拟孔隙溶液中的锈蚀行为与临界氯离子浓度，探索珊瑚骨料“微泵缓释”阻锈剂的迁移作用与机理，氯离子扩散与阻锈剂缓释的协同机制；研究氯离子点蚀钢筋的再钝化行为、钝化膜修复与重建的电化学机理，提高钢筋表面修复型钝化膜的抗点蚀能力。基于电化学阻抗谱出现钝化膜的高频容抗弧特征，建立能表征钝化膜或吸附膜的等效电路新模型，准确把握珊瑚混凝土钢筋锈蚀机理的本质。本项目将为钢筋珊瑚混凝土结构提供基本的钢筋防腐理论和技术方法，推动我国岛礁珊瑚混凝土结构科学技术的进步。

本项目研究了全珊瑚海水混凝土（CASC）中钢筋表面“钝化膜”破坏与修复过程，获取了表征“钝化膜”或“吸附膜”对应的时间常数及其等效电路单元，创建了能够表征不同种类阻锈剂在CASC中不同阶段的“缓释”作用效应的电化学等效电路模型，提出并验证了适用于描述CASC中钢筋锈蚀电化学规律的“统一”等效电路模型；分析了CASC中不同种类阻锈剂“微泵缓释”迁移作用及其机理，验证了珊瑚骨料“储存泵池”预吸收工艺制度的可靠性；研究了不同因素对CASC中钢筋锈蚀行为的影响，揭示了在“阻锈剂缓释”作用下CASC内点蚀钢筋表面的再钝化电化学机理。本项目为钢筋珊瑚混凝土结构提供基本的钢筋防腐理论和技术方法，推动我国岛礁珊瑚混凝土结构科学技术的进步。