裂缝对滨海混凝土结构中钢筋锈蚀的影响机制及对策研究

本项目以滨海钢筋混凝土结构的耐久性为背景，以合理诱导的预设裂缝为研究对象，研究裂缝对混凝土中钢筋锈蚀行为的影响机制及对策。主要研究目标为阐明裂缝对混凝土介质传输特性的影响，构建开裂混凝土中水分及氯离子等介质的传输模型和碳化速度模型；统计钢筋锈蚀状态与裂缝位置、裂缝形态的关联度，确定开裂混凝土中钢筋腐蚀阳极分布特征及经时演变规律；阐明碳化及氯离子等侵蚀性介质与裂缝协同作用下的钢筋锈蚀机理，建立开裂混凝土中钢筋锈蚀劣化模型；结合介质传输及钢筋锈蚀速率的裂缝宽度阈值范围，提出与滨海服役环境相匹配的裂缝处置措施。通过项目研究可充分揭示开裂混凝土结构的耐久性劣化规律，为滨海混凝土结构的裂缝控制及裂缝修复提供科学依据。

This research focuses on durability of reinforced concrete structure in coastal environment. The aim of the project is to investigate the influencing mechanism of artificial cracks on the corrosion of reinforcement in coastal concrete structure and its prevention methods. The effect of cracks on the mass transport in the concrete will be described, and the moisture and chloride transport models in the cracked concrete as well as the carbonation model will be proposed.The distribution and time-dependent evolution of corrosion anode is determined, which is based on the relation of reinforcement corrosion to the location and geometry of cracks.The mechanism of reinforcement corrosion under the synergetic effect of cracks and corrosive environment such as carbonation and chloride attack will be verified, and finally, a model of the concrete deterioration attributed to the reinforcement corrosion will be carried out. This project also intends to provide efficient methods to reduce the effect of cracks according to the mass transport in the concrete and threshold value of the crack related to the corrosion rate. The research not only constituents a significant contribution to the deterioration law of concrete structures, but also provides a scientific method to the crack control and repair of the concrete structure in coastal regions.