混凝土中钢筋锈蚀的研究

Study on Corrosion of Reinforcement in Concrete

钢筋腐蚀对混凝土耐久性和安全性有很大影响。笔者阐述了研究钢筋锈蚀的原因、目的和意义;研究了钢筋在未开裂和裂缝状态下的锈蚀机理,钢筋的腐蚀过程实质上是一个电化学反应过程;影响钢筋锈蚀的主要因素有混凝土的密实度、混凝土碳化、环境湿度、氯离子侵入等;对钢筋腐蚀过程中的4个阶段进行了研究;从锈后钢筋截面面积损失率对结构受力的影响进行讨论;从正常使用寿命和承载能力使用寿命两方面对在役混凝土结构剩余寿命进行预测;并提出了钢筋锈蚀应采取的预防措施,以提高结构的耐久性和安全性,减少耐久性破坏造成的损失。研究的成果在工程上具有一定的理论意义和实用价值。

Reinforcement corrosion has large impact on durability and safety of the concrete. The reason, purpose and significance in study of reinforcement corrosion are described. Corrosion mechanism in cracked and not cracked states is introduced. The process of reinforcement corrosion essentially is a process of electrochemical reaction. The main causation of reinforcement corrosion includes concrete compactness, concrete carbonization, environment humidity, chloride ion invasion and so on. Four stages of the reinforcement corrosion process are studied. The influence of percentage loss of sectional area on structural stress is discussed. From the normal serviceable and load serviceable longevity, the residual life of the in-service concrete structure is predicted. The preventive measures for reinforcement corrosion are proposed so as to enhance durability and safety of the structure and reduce the loss due to durability damage. The result has theoretical significance and practical value in engineering project.