湿地环境钢筋暴露腐蚀及其对墩柱性能的影响

Exposed Corrosion of Reinforcement in Wetland Environment and Its Effect on the Performance of Pier Columns

湿地环境下墩柱钢筋暴露在外往往会引起锈蚀进而造成钢筋混凝土结构开裂,钢筋使用前锈蚀不仅会影响墩柱等结构的力学性能,对混凝土结构耐久性也产生不利影响。本文以窑头特大桥墩柱钢筋锈蚀问题为依托,创新采用图像分析法,通过光学显微镜获取钢筋表面微观图像,基于图像分析软件对钢筋锈蚀微观图像进行定量分析与计算,以探索钢筋锈蚀率随钢筋暴露时间关系,以及钢筋与混凝土之间粘结力变化规律,并探讨影响桥梁墩柱耐久性的因素和常用防护方法,以期为后期墩柱施工提供借鉴意义。

The steel bars of pier columns will cause concrete corrosion and then cracking of reinforced concrete structures when exposed in wetland environment.The corrosion of steel bars before use will not only affect the mechanical properties of pier columns,but also adversely affect concrete durability.In this paper,based on the corrosion problem of steel bars in the pier columns of Yaotou Super Large Bridge,image analysis was innovatively adopted to obtain microscopic images of reinforcement surface through a microscope,and quantitative analysis and calculation were carried out on microscopic images of reinforcement corrosion combined with image analysis software,so as to explore the relationship between the corrosion rate of steel bars and the exposure time of steel bars in the air,and the change law of the bonding force between steel bar and concrete was also explored.Besides,the factors influencing the durability of bridge pier columns and common protection methods of concrete were discussed,which were expected to provide reference for the later construction of piers and columns.