This paper presents a review of the deterioration of concrete under seawater attack with particular interests in field exposure. The research reported in the literature has shown that salinity of seawater in different areas varies considerably but the type of ions and their proportion are similar. Because of this variation, laboratory studies should use specific artificial seawater to simulate on field environments. The phase changes induced by chloride, magnesium and sulfate ions contained in seawater are reviewed. The interaction between hydrates and chloride ion can lead to the formation Friedel's and Kuzel's salts. Magnesium ion can replace the calcium in Portlandite, and lowers the alkalinity of pore solution and eventually destabilizes C-S-H gel. The expansive ettringite is inhibited at the presence of chloride ions. At the tidal zone, the phase change mainly occurs on the surface of concrete, which weakens the structure and leads to spalling and delamination under the physical attack of the wave. Based on the existing deterioration mechanisms, the protocols to enhance the durability performance of marine concrete are also reviewed, such as using supplementary cementitious materials (SCMs) to mitigate rate of chloride penetration and, more promisingly, to use alternative binder systems. This paper also proposes a concept of designing a more durable concrete cover system by enhancing the chemical stability of cement hydrates, rapid self-healing and intelligent alkalinity control.

本文对海水侵蚀下混凝土的变质进行了综述，特别是在野外曝晒中。文献报道的研究表明，不同地区的海水盐度差异很大，但离子的类型及其比例相似。由于存在这种差异，实验室研究应使用特定的人造海水来模拟野外环境。综述了海水中氯离子，镁离子和硫酸根离子引起的相变。水合物与氯离子之间的相互作用可导致形成弗里德氏盐和库泽尔盐。镁离子可以代替硅酸盐中的钙，降低孔隙溶液的碱度，最终使CSH凝胶不稳定。膨胀的钙矾石在氯离子的存在下被抑制。在潮汐区，相变主要发生在混凝土表面，这会削弱结构并在波浪的物理攻击下导致剥落和分层。基于现有的恶化机制，还对提高船用混凝土耐久性的协议进行了审查，例如使用补充胶凝材料（SCM）来降低氯化物的渗透率，更可喜的是，使用替代性粘结剂系统。本文还提出了一种通过增强水泥水合物的化学稳定性，快速的自我修复和智能的碱度控制来设计更耐用的混凝土覆盖系统的概念。基于现有的劣化机制，还对提高船用混凝土耐久性的方案进行了评估，例如使用补充胶凝材料（SCM）来降低氯化物的渗透率，更可喜的是，使用替代的粘结剂体系。本文还提出了一种通过增强水泥水合物的化学稳定性，快速的自我修复和智能的碱度控制来设计更耐用的混凝土覆盖系统的概念。基于现有的劣化机制，还对提高船用混凝土耐久性的方案进行了评估，例如使用补充胶凝材料（SCM）来降低氯化物的渗透率，更可喜的是，使用替代的粘结剂体系。本文还提出了一种通过增强水泥水合物的化学稳定性，快速的自我修复和智能的碱度控制来设计更耐用的混凝土覆盖系统的概念。