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

该提案解决了现有钢筋混凝土结构的抗震和使用寿命评估和改造方面的未决问题。 一般框架是基于性能的，其中验收标准表示为单个构件和完整结构系统的变形能力估计（DC）。 虽然已建立的代码提供的方法，估计直流，与实验证据的比较表明，这个参数是非常不好的理解与不可接受的高裕度的不确定性真实的值。 出于这个原因，本研究的主要目的是提高对钢筋混凝土DC力学的理解，并将基于性能的评估方法扩展到腐蚀结构。 在此背景下，该项目还将制定受腐蚀影响的结构的使用寿命估计和性能标准的方法。 在组装相关数据库后，将对可用的实验证据进行集体审查，并将在实验室进行额外的测试，并通过先进的非线性有限元研究，以澄清重要参数的物理意义，如屈服穿透，塑性铰定义，轴向载荷效应和破坏模式的层次结构，对DC。 对于受腐蚀影响构件的DC，这将扩展到包括腐蚀渗透深度、钢筋面积损失和保护层脆化。 特别强调的是，将放在改进的代表性的债券和钢筋屈服的应变发展能力的钢筋的影响，将进行相关的实验，以研究其对DC的影响，包括在实验室模拟腐蚀后，部分腐蚀的锚具/搭接接头的情况。 DC的改进估计的应用程序的案例研究，特别是当占的重要影响的屈服传播的剪切跨度的成员，将开发作为基于性能的设计和评估的模型示例。*** 应变硬化水泥基复合材料（SHCC）的结构性能将进行实验研究，以解决新结构设计中的开放问题（旨在通过最大限度地减少所需的钢筋来简化施工），并将其应用于旧结构中遇到的系统性问题的创新修复解决方案中。通过设计纳米结构（通过纳米添加剂）和结合不同类型的合成纤维和纤维涂层来实现SHCC的功能化，将用于各种预期应用。试验将探索用SHCC建造的结构构件的结构行为，以便为设计规则的制定提供基础，以支持在新建筑中引入它们，以及通过利用SHCC由于其纤维含量而提供的内部限制来改造方法。

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.**