钢筋混凝土结构在暴露于富含氯化物的环境中时,容易受到钢筋的腐蚀,这会严重影响其耐用性。为了解决这个问题,全面了解混凝土中氯离子扩散的影响因素至关重要。本文对混凝土中氯离子迁移的国内外研究现状进行了综述,关注六个关键因素:水胶比,添加剂含量,裂缝宽度,环境温度,相对湿度,和干湿循环。结果表明,氯离子在混凝土中的扩散系数随着水胶比的增加而增加,随着添加剂含量的增加而减小。此外,更宽的裂缝导致更大的氯离子扩散。混凝土抗氯离子渗透性随温度和湿度的升高而降低,干湿循环进一步加速了氯离子的扩散。文章最后通过讨论各种防腐措施,例如使用缓蚀剂,表面涂层,和电化学处理,以确保结构的寿命。最后,提出了未来研究的方向。
Reinforced concrete structures are prone to the corrosion of steel bars when exposed to chloride-rich environments, which can severely impact their durability. To address this issue, a comprehensive understanding of the factors influencing chloride ion diffusion in concrete is essential. This paper provides a summary of recent domestic and foreign research on chloride ion transport in concrete, focusing on six key factors: water-binder ratio, additive content, crack width, ambient temperature, relative humidity, and dry-wet cycles. The findings show that the diffusion coefficient of chloride ions in concrete increases with a higher water-binder ratio and decreases with increased additive content. Additionally, wider cracks result in a greater diffusion of chloride ions. The permeability resistance of concrete to chloride ions decreases with rising temperature and humidity, and dry-wet cycles further accelerate the diffusion of chloride ions. The article concludes by discussing various anti-corrosion measures, such as the use of corrosion inhibitors, surface coatings, and electrochemical treatments, to ensure the longevity of the structure. Finally, directions for future research are proposed.