Durability of concrete

尽管混凝土技术有所发展，但极端环境下的混凝土仍在过早退化。在某种程度上，这是由于规范或施工方法的不足，但它也是由于缺乏对影响耐久性的所有因素的了解。水泥浆体基质和膏体-骨料界面区域的孔隙结构和由此产生的流体渗透阻力决定了混凝土对大多数破坏原因的耐久性。在本提案中，将继续研究这些特性，并应用于抵抗：氯化物侵入，钢筋腐蚀，在除冰盐存在下的冷冻和解冻，碱集料反应和硫酸盐抗性。耐久性的其他方面，如抗裂性（热和潮湿相关的收缩）和改进的基于耐久性的性能规范也在研究中。

In spite of developments in concrete technology, concrete in extreme environments continues to prematurely deteriorate. In part this results from inadequate specifications or construction methods, but it also results from a lack of understanding of all the factors which influence durability. The pore structure and resultant fluid penetration resistance of the cement paste matrix and paste-aggregate interfacial regions govern the durability of concrete to most causes of distress. In this proposal, these properties will continue to be studied with applications to resistance to: chloride ingress, reinforcement corrosion, freezing and thawing in the presence of de-icer salts, alkali-aggregate reactions, and sulphate resistance. Other aspects of durability such as crack resistance (to thermal and moisture related shrinkage) and improved durability- based performance specifications are also being studied.