Seismic and Service Life Assessment of Reinforced Concrete Structures and Novel Cementitious Materials Application for Durable and Resilient Construction

钢筋混凝土结构的抗震和使用寿命评估以及新型水泥材料在耐用和弹性建筑中的应用

• 批准号: RGPIN-2016-05324
• 负责人: Pantazopoulou, Stavroula
• 金额: $ 1.97万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709250
• 关键词: Seismic; Service; Life; Assessment; Reinforced

The proposal addresses open issues in seismic and service life assessment and retrofit of existing reinforced concrete construction. The general framework is performance based, whereby the acceptance criteria are expressed in terms of Deformation Capacity estimates (DC) for the individual members and complete structural systems. Although the established Codes provide methods for estimation of DC, comparison with experimental evidence illustrate that this parameter is very poorly understood with unacceptably high margin of uncertainty to real values. For this reason the main objective of the study is to develop improved understanding of the mechanics that underly the DC of reinforced concrete, and to extend the performance based methods of assessment to corroded structures. In this context the project will also develop methods for service life estimation and performance criteria for corrosion affected structures. The available experimental evidence will be reviewed collectively after assembly of relevant databases, and additional tests will be undertaken in the lab and through advanced nonlinear finite element studies in order to clarify the physical significance of important parameters such as yield penetration, plastic hinge definition, axial load effects, and hierarchy of failure modes, on DC. This will be extended to include depth of corrosion penetration, steel area loss and embrittlement of the cover, for DC of corrosion affected members. Particular emphasis will be placed in improved representation of bond and the effects of bar yielding on strain development capacity of reinforcement; relevant experiments will be conducted to study its effect on DC, including the case of partially corroded anchorages/lap splices after simulated corrosion in the lab. Case studies of application of the improved estimates of DC, particularly when accounting for the important effects of yield spreading in the shear span of members, will be developed as model examples of performance based design and assessment. The structural performance of strain-hardening cementitious composites (SHCC) will be studied experimentally to resolve open issues in design of new structures (aiming for simpler construction through minimization of required stirrup reinforcement), and to implement them in innovative repair solutions of the systemic problems encountered in old structures. Functionalization of SHCC by engineering the nanostructure (through nano-additives) and combining different types of synthetic fibres and fibre coatings will be pursued for the various intended applications. Tests will explore the structural behavior of structural members constructed with SHCC so as to provide a basis for development of design rules to support their introduction in new construction but also in retrofitting methods, by taking advantage of the internal confinement afforded by SHCC due to their fiber content.

该提案解决了现有钢筋混凝土结构的地震和服务寿命评估和改造中的开放问题。 总体框架是基于绩效的，因此，根据个人成员和完整的结构系统的变形容量估计（DC）来表达接受标准。 尽管已建立的代码提供了估计DC的方法，但与实验证据进行了比较，表明该参数对实际值的不确定性不确定性很高，对此参数的理解很差。 因此，该研究的主要目的是提高对钢筋混凝土DC的机制的了解，并将基于绩效的评估方法扩展到腐蚀结构。 在这种情况下，该项目还将开发用于腐蚀影响结构的服务寿命估计和性能标准的方法。 在组装相关数据库之后，将共同审查可用的实验证据，并通过实验室和先进的非线性有限元研究进行其他测试，以阐明重要参数的物理意义，例如产量铰链，塑料铰链定义，轴向载荷效应，轴向负载效应和失败模式的层次结构。 对于受影响的成员的DC，这将扩展到包括腐蚀渗透深度，钢面积损失和覆盖的覆盖。 特别强调将改善键的代表和棒屈服对应变发展能力的影响；将进行相关的实验以研究其对DC的影响，包括在实验室中模拟腐蚀后部分腐蚀的锚固/lap剪接的情况。 将在成员的剪切范围内考虑到产量扩散的重要影响的案例研究，尤其是在考虑到基于绩效设计和评估的模型示例时。 将通过实验研究应变固定胶质复合材料（SHCC）的结构性性能，以解决新结构设计中的开放问题（通过最小化所需的马strup钢筋来实现更简单的结构），并在旧结构中遇到的系统性问题的创新维修解决方案中实施它们。通过工程（通过纳米添加剂）对SHCC进行功能化，并将不同类型的合成纤维和纤维涂层结合起来，以用于各种预期的应用。测试将探讨用SHCC构建的结构成员的结构性行为，以提供设计规则的基础，以支持其在新结构中的介绍，并通​​过利用SHCC由于其纤维含量而提供的内部限制来改造方法。