Application of Strain Hardening Cementitious Materials in Seismic Design and Retrofit of Structures

应变硬化胶凝材料在结构抗震设计与改造中的应用

• 批准号: RGPIN-2022-05454
• 负责人: Pantazopoulou, Stavroula
• 金额: $ 2.26万
• 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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=758070
• 关键词: Application; Strain; Hardening; Cementitious; Materials

A route to reduce the environmental impact of concrete is to aim for materials that are durable, resilient, and strong with reduced energy impact and demand on natural resources; and to aim for structures that have a long service life while providing their users with safety against extreme events such as earthquakes. The advent of the development of Strain Hardening Cementitious Composites (SHCC) opens up an opportunity to address several of these concerns by taking advantage of the unique properties of this strain-resilient class of concrete materials that combine high strength with excellent crack control and significantly improved durability over common concrete. SHCCs have not yet been integrated in structural design, except for the critical regions of a few bridges with severe environmental exposure. Their widespread use has been delayed due to cost and lack of general design specifications. Thus, the full potential of SHCC is yet to be realized both in new construction and in retrofits. The strain-ductility in tension and the large range of available compressive and tensile strengths makes SHCC ideal for seismic design and rehabilitation of Structures. The proposed work will focus on formulation of a Performance-Based Design Framework for seismic resistant SHCC Structures and for seismic retrofit solutions using SHCCs. Material characterization under cyclic tension/compression, pertinent test setups, component and subassembly tests of structural systems that are either designed or retrofitted with SHCC under cyclic displacement reversals representing earthquake effects will be conducted. Hysteretic constitutive laws for advanced nonlinear simulation of structures made or retrofitted with SHCC will be formulated. The objective is to develop design models for dimensioning and detailing seismic resistant structures and retrofit schemes comprising SHCCs while exploiting the deformability of the material to reduce reinforcement detailing without compromise in performance. Results will feed into a mounting effort for the establishment of a design code for seismic design and upgrading of new and old reinforced concrete structures using SHCCs, to enable practical implementation of this technology for high performing structures and structural retrofits. The study will serve as the testbed for pre-normative evaluation of the seismic design provisions, thus benefiting the Canadian Construction Industry (material producers, precast industry and designers all benefit from new structural systems to achieve seismic resilience). Sustainability effected by prolonged service life and reduced maintenance requirements of structures is an added benefit to Canadian Society at large. The research program will provide exceptional opportunities to HQPs to become versed to novel technologies that will help them stand out in industry and academia, while also addressing many UN-SDGs; EDI is a driving consideration for planning the proposed training environment.

减少混凝土对环境影响的一种途径是采用耐用、有弹性和坚固的材料，减少对能源的影响和对自然资源的需求；我们的目标是使结构具有较长的使用寿命，同时为用户提供抵御地震等极端事件的安全保障。应变硬化胶凝复合材料（SHCC）的出现为解决这些问题提供了一个机会，利用这种应变弹性混凝土材料的独特特性，将高强度与出色的裂缝控制相结合，并显著提高了普通混凝土的耐久性。除了少数环境暴露严重的桥梁的关键区域外，shcc尚未纳入结构设计。由于成本和缺乏通用的设计规范，它们的广泛使用被推迟了。因此，在新建筑和改造方面，住房中心的全部潜力仍有待实现。SHCC在拉伸下的应变延展性和大范围的可用抗压和抗拉强度使其成为结构抗震设计和修复的理想材料。拟议的工作将侧重于制定基于性能的抗震SHCC结构设计框架和使用SHCC的抗震改造解决方案。将进行循环拉伸/压缩下的材料特性、相关试验设置、用SHCC设计或改造的结构系统在代表地震效应的循环位移逆转下的组件和组件试验。将制定用SHCC制造或改造的结构的高级非线性模拟的迟滞本构律。目标是开发设计模型，以确定抗震结构的尺寸和细节，以及包括shcc的改造方案，同时利用材料的可变形性，在不影响性能的情况下减少钢筋细节。研究结果将有助于建立抗震设计规范，并利用低碳混凝土对新旧钢筋混凝土结构进行升级，以便在高性能结构和结构改造中实际实施这项技术。这项研究将作为抗震设计规定的预规范评估的试验台，从而使加拿大建筑业受益（材料生产商、预制件行业和设计师都受益于新的结构系统，以实现抗震弹性）。延长的使用寿命和减少的维护要求对结构的可持续性影响是对加拿大社会的一个额外好处。该研究项目将为hqp提供掌握新技术的绝佳机会，帮助他们在工业界和学术界脱颖而出，同时实现许多联合国可持续发展目标；EDI是规划所提议的培训环境的主要考虑因素。