海洋环境混凝土结构非锈胀裂缝部位钢筋腐蚀表征及原位实体监测原理

Taking the concrete structure of the operating Zhoushan Sea-Crossing Bridge and the Marine Exposure Station (under construction) as the research basis, this study explains the electrochemical principles of rebar corrosion at the transverse crack position under coupled effects of multiple variables in marine environment. We will conduct experiments of online acquisition of electrochemical noise spectrum that is sensitive to the electrochemical reaction process, type of reactions, limiting factors of reaction, the corrosion status and appearance features. The main variables are the corrosion of different marine zones (tidal zone, splash zone, etc.), the macro features of transverse crack, the thickness and the alkalinity of concrete cover. The auxiliary parameters are measured concrete density, water ratio, resistance and the concentration of chloride ions. Through noise filtering, diagram reading and data analysis of the measured corrosion current and the noise spectrum of electrical potential, we will obtain quantitative noise signals identification model of various electrochemical corrosion types and physical features. We will also create practical quantitative methods of evaluation of rebar corrosion at the transverse crack position and build the rebar corrosion models. We will then describe the mechanism of dynamic monitoring of the rebar corrosion process at the transverse crack position and write the universal program for building the predictive models of the structure durability. This will set the key theoretical foundation for the development of the monitoring system of interventional rebar corrosion at the crack position and effective methods of corrosion control.

本研究以运营中的舟山跨海大桥混凝土结构和建设中的海洋暴露实验站为研究平台, 以海洋腐蚀区带(潮差区、飞溅区等)、非锈胀裂缝宏观特征、保护层厚度、混凝土化学碱度为主要变量, 以实测混凝土密实度、含水率、电阻率、氯离子浓度分布等为辅助参数, 采用实时在线采集与电化学反应过程、反应类别、反应受控瓶颈、以及腐蚀状态和形貌特征敏感的电化学噪声谱的实验和研究方法, 阐明海洋环境多因素耦合作用下的非锈胀裂缝处钢筋腐蚀电化学机理。通过对捕获的腐蚀电流和腐蚀电位的噪声谱进行滤噪、解图和数据解析, 得到不同电化学腐蚀类型和物理形貌的系列定量化噪声信号识别模式, 建立符合工程实际的混凝土非锈胀裂缝部位钢筋腐蚀的定量评价方法和钢筋腐蚀模型。从而实现对非锈胀裂缝部位钢筋腐蚀全过程动态监测的机理描述, 编制建立结构耐久性预测模型的通用程序, 为裂缝部位介入式钢筋腐蚀监测系统的研发和进行有效的腐蚀控制奠定关键理论基础。

本研究以在役的舟山跨海大桥混凝土结构和建设的海洋暴露实验站为研究平台, 以海洋腐蚀区带(潮差区、飞溅区等)、非锈胀裂缝宏观特征、保护层厚度、混凝土化学碱度为主要变量, 以实测混凝土密实度、含水率、电阻率、氯离子浓度分布等为辅参数, 采用l了实时在线采集与电化学反应过程、反应类别、反应受控瓶颈、以及腐蚀状态和形貌特征敏感的电化学噪声谱的实验和研究方法, 阐明了海洋环境多因素耦合作用下的非锈胀裂缝处钢筋腐蚀电化学机理。通过对捕获的腐蚀电流和腐蚀电位的噪声谱进行滤噪、解图和数据解析, 得到了不同电化学腐蚀类型和物理形貌的系列定量化噪声信号识别模式, 建立了符合工程实际的混凝土非锈胀裂缝部位钢筋腐蚀的定量评价方法和钢筋腐蚀模型。从而实现了对非锈胀裂缝部位钢筋腐蚀全过程动态监测的机理描述, 编制建立了结构耐久性预测模型的通用程序方法, 为裂缝部位介入式钢筋腐蚀监测系统的研发和进行有效的腐蚀控制奠定了关键理论基础。