Durability of Concrete

尽管混凝土技术不断发展，但极端环境下的混凝土仍会过早劣化。这部分是由于使用新材料而没有充分评估潜在的影响，或由于使用不适当的规格或施工方法，但也是由于缺乏对影响耐久性的所有因素的了解。水泥浆体基质和浆体-骨料界面区域的孔结构和由此产生的流体渗透阻力决定了混凝土的耐久性。具体而言，有四个主要的研究重点领域：（1）更好地表征孔结构、流体进入机制和改进暴露于氯化物环境的混凝土的使用寿命的预测，（2）改进碱-硅反应的预测，（3）开发混凝土抵抗不同硫酸盐侵蚀机制的新方法，以及（4）降低早期非结构性开裂的风险。*总体目标是增加对混凝土劣化机制的理解，开发创新的解决方案和测试，并通过采用性能测试和规范来促进行业的变革，从而提高混凝土的耐久性并延长其使用寿命。

In spite of developments in concrete technology, concrete in extreme environments continues to prematurely deteriorate. In part this results from utilization of new materials without adequate evaluation of potential impacts, or from use of 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. Specifically, there are four main areas of research focus: (1) better characterization of pore structure, fluid ingress mechanisms and improving prediction of service life of concretes exposed to chloride environments, (2) improving the prediction of alkali-silica reaction, (3) developing new methodologies for concrete's resistance to different sulfate attack mechanisms, and (4) reducing the risk of early-age non-structural cracking.****The overarching objectives are to increase the understanding of deterioration mechanisms in concrete, to develop innovative solutions and tests and use them to promote transformative changes in the industry through adoption of performance tests and specifications that will improve the durability and extend the service life of concrete.******