Durability of Concrete

混凝土的耐久性

• 批准号: 108067-2012
• 负责人: Hooton, Douglas
• 金额: $ 3.42万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569151
• 关键词: Durability; Concrete

In spite of developments in concrete technology, concrete in extreme environments continues to prematurely deteriorate. In part, this results from the use of new materials without adequate consideration of side effects, but mostly from the use of inadequate tests, specifications or construction methods, and also 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 in resistance to: chloride ingress, reinforcement corrosion, freezing and thawing, 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. Specifically, there are several areas of research focus: (1) development of test methods, especially related to characterizing pore structure, fluid transport through concrete, alkali-silica reaction, salt scaling, sulphate resistance, and volume stability, (2) prediction of performance of fresh and early-age properties of cementitious materials in combination with chemical admixtures, (3) developing procedures for evaluating the role of low-alkali cements in mitigating alkali-silica reaction, (4) increased use of industrial by-products and waste materials in concrete, (5) improvements to evaluation of residual service life of concretes exposed to chloride environments, (6) development and implementation of new durability performance test methods and practices in codes and standards.

尽管混凝土技术不断发展，但极端环境下的混凝土仍然会过早恶化。部分原因是在使用新材料时没有充分考虑副作用，但主要是由于使用了不充分的测试、规范或施工方法，以及对影响耐久性的所有因素缺乏了解。水泥浆基体和浆体-集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损坏原因的耐久性。在该提案中，将继续研究这些特性及其在抗氯化物侵入、钢筋腐蚀、冻融、碱骨料反应和抗硫酸盐方面的应用。耐久性的其他方面，例如抗裂性（针对热和湿气相关的收缩）和改进的基于耐久性的性能规格也在研究中。 具体来说，有几个研究重点领域：(1) 测试方法的开发，特别是与表征孔隙结构、混凝土中的流体传输、碱硅反应、盐结垢、硫酸盐抗性和体积稳定性相关的测试方法，(2) 预测水泥材料与化学外加剂结合的新鲜和早期性能的性能，（3）开发评估低碱水泥在减轻碱硅反应中的作用的程序，（4）增加工业副产品和废物的使用混凝土中的材料，(5) 改进暴露于氯化物环境中的混凝土剩余使用寿命的评估，(6) 制定和实施新的耐久性能性能测试方法以及规范和标准中的实践。