Concrete Durability: Linking Material Properties and Field Performance

混凝土耐久性：将材料特性与现场性能联系起来

• 批准号: RGPIN-2016-04873
• 负责人: Thomas, Michael
• 金额: $ 2.26万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=666764
• 关键词: Concrete; Durability; Linking; Material; Properties

Concrete is the most widely-used construction material in the world but is often poorly understood and inadequately designed leading to premature deterioration in many aggressive exposure conditions. The applicant's research program is aimed at developing a fundamental understanding of the deterioration processes that can occur in different environments, determining the appropriate material properties to resist the destructive forces, quantifying and predicting rates of deterioration, and validating experimental observations with field performance studies. The main focus of the ongoing research program is to continue the development and improvement of appropriate test methods and predictive models for evaluating concrete's resistance to some of the more prevalent forms of deterioration; these are: (i) chloride ingress and corrosion of steel, (ii) alkali-silica reaction, (iii) sulfate attack, and (iv) combined ASR and freeze-thaw. The main objectives of the research program are: ***1. Validation of existing models for predicting chloride penetration, including models developed by the applicant and various collaborators. Validation will be conducted through ongoing long-term laboratory and field-exposure testing, and sampling of structures. A two-phase model will be developed to include the impact of carbonation as it penetrates from the surface. ***2. Development of improved test methods for alkali-silica reaction (ASR) with exposure conditions designed to provide sufficient moisture without allowing the ingress or egress of alkalis from the concrete. Validation and calibration will be performed using data from numerous long-term exposure sites that have been established by the applicant and collaborators, and through the use of data from existing structures that have been monitored for decades. ***3. Synergy between ASR and freeze-thaw attack. ASR results in expansion and cracking of concrete which may not in itself result in the end of the life of a structure but which may render it more vulnerable to other processes. Concretes with a range of ASR-damage levels and various degrees of saturation will be exposed to freeze-thaw cycles. This component of the research program (ASR-freeze/thaw) will conducted in collaboration with Jason Weiss of Oregon State University (previously with Purdue University). ***4. Development of an improved test for evaluating sulfate resistance of concrete. The test will be benchmarked using data from a sulfate exposure site. **

混凝土是世界上使用最广泛的建筑材料，但人们通常对混凝土知之甚少且设计不充分，导致在许多恶劣的暴露条件下过早恶化。申请人的研究计划旨在对不同环境中可能发生的劣化过程有一个基本的了解，确定抵抗破坏力的适当材料特性，量化和预测劣化率，并通过现场性能研究验证实验观察。正在进行的研究计划的主要重点是继续开发和改进适当的测试方法和预测模型，以评估混凝土对一些更普遍的恶化形式的抵抗力；它们是：(i) 氯化物进入和钢腐蚀，(ii) 碱-硅反应，(iii) 硫酸盐腐蚀，以及 (iv) ASR 和冻融相结合。该研究计划的主要目标是：***1。验证用于预测氯化物渗透的现有模型，包括申请人和各个合作者开发的模型。验证将通过持续的长期实验室和现场暴露测试以及结构采样进行。将开发一个两相模型，以包含碳化作用从表面渗透时的影响。 ***2.开发改进的碱硅反应 (ASR) 测试方法，其暴露条件旨在提供足够的水分，而不允许碱从混凝土中进出。验证和校准将使用来自申请人和合作者建立的众多长期暴露地点的数据以及来自已经监测了数十年的现有结构的数据来进行。 ***3. ASR 和冻融攻击之间的协同作用。 ASR 会导致混凝土膨胀和开裂，这本身可能不会导致结构寿命的结束，但可能会使其更容易受到其他过程的影响。具有一系列 ASR 损伤水平和不同饱和度的混凝土将暴露于冻融循环。该研究计划的这一部分（ASR 冷冻/解冻）将与俄勒冈州立大学（之前与普渡大学）的 Jason Weiss 合作进行。 ***4.开发评估混凝土抗硫酸盐性能的改进测试。该测试将使用来自硫酸盐暴露地点的数据进行基准测试。 **