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

点击翻译按钮获取中文摘要

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.