Ultra-high-performance concrete (UHPC) retrofits for increased blast protection of concrete and masonry structures

超高性能混凝土 (UHPC) 改造可增强混凝土和砖石结构的防爆性能

• 批准号: RGPIN-2020-06871
• 负责人: Aoude, Hassan
• 金额: $ 1.89万
• 依托单位: University of Ottawa
• 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=749459
• 关键词: Ultra; performance; concrete; UHPC; retrofits

Recent bomb attacks around the world have demonstrated the vulnerability of existing buildings to blast loads. Events such as the Lac-Mégantic disaster and Toronto Propane Explosion also highlight the vulnerability of Canada's built infrastructure to accidental and industrial explosions. Bridges are also vulnerable to blast threats, and pose unique design challenges due to their open access. In addition, unlike buildings, key structural components in bridges are directly loaded and therefore may be exposed to large blast loads at low standoff. Until recently, blast-resistant design was not common in the design of buildings and bridges in Canada; thus, a large inventory of existing buildings and bridges are in need of retrofits to increase blast resilience and ensure safety and security of Canadians. Previous blast incidents such as the Oklahoma City Bombing have raised awareness of the need for retrofitting columns to increase the survivability of concrete buildings and bridges. Masonry walls are another vulnerable structural type found in many older buildings in Canada, either as infill or structural walls. Modern codes require minimum steel in masonry construction, but older buildings had no such requirement; thus unreinforced masonry (URM) walls in existing buildings are vulnerable to collapse under very low out-of-plane blast loads. Such walls can fail dramatically, with high speed projectiles that can injure building occupants. Ultra High Performance Concrete (UHPC) is a new class of advanced cement-based composite with remarkable strength, tensile resistance, toughness and damage tolerance. These unique features make UHPC an ideal material for blast-resistant design applications. This material's high bond capacity, coupled with its ability to be cast in very thin yet strong layers also make it an ideal material to retrofit vulnerable structures against blasts. The long term goal of the proposed research program is to develop novel blast retrofit strategies using advanced cement-based composite materials for critical Canadian infrastructure. The long term objectives include the development of retrofit methodologies, analytical tools and design procedures that can capture dynamic response of retrofitted elements. The short-term objective is to develop novel UHPC-retrofits for the protection of structural and non-structural elements in concrete and masonry structures. The scope will consist of four main tasks; i) materials research to investigate the high-strain behavior and bond response of the UHPC retrofits, ii) application of UHPC-jacketing in concrete building/bridge columns, iii) application of UHPC-overlays to masonry walls; iv) development of analytical models for predicting the blast response of the UHPC-retrofits. It is envisioned that the research program will result in the development of best practice guidelines and provisions for CSA Standards for the benefit of the Canadian construction industry.

世界各地最近发生的炸弹袭击事件表明，现有建筑物容易受到爆炸荷载的影响。梅冈蒂克湖灾难和多伦多丙烷爆炸等事件也凸显了加拿大的建筑基础设施容易受到意外和工业爆炸的影响。 ，并且由于其开放通道而带来独特的设计挑战。此外，与建筑物不同，桥梁中的关键结构部件是直接加载的，因此可能会在低隔距下承受巨大的爆炸荷载，直到最近，抗爆炸设计在桥梁中并不常见。设计加拿大的大量建筑物和桥梁需要进行改造，以提高抗冲击能力并确保加拿大人的安全和保障，例如俄克拉荷马城爆炸事件。改造柱子以提高混凝土建筑物和桥梁的生存能力 砖石墙是加拿大许多旧建筑中的另一种脆弱结构类型，无论是填充墙还是结构墙，现代规范都要求砖石建筑中的钢材用量最少，但旧建筑没有这样的要求。 ; 因此现有建筑物中的无筋砖石墙 (URM) 在极低的平面外爆炸荷载下很容易倒塌，高速射弹可能会伤害建筑物内的人员。一种先进的水泥基复合材料，具有卓越的强度、抗拉性、韧性和损伤容限，这些独特的特性使 UHPC 成为防爆设计应用的理想材料，并且具有高粘结能力和铸造能力。非常薄而坚固的层也使其成为改造脆弱结构以抵御爆炸的理想材料。拟议研究计划的长期目标是使用先进的水泥基复合材料开发新颖的爆炸改造策略，以实现加拿大的关键基础设施目标。开发能够捕获改造元件动态响应的改造方法、分析工具和设计程序。短期目标是开发新型 UHPC 改造，以保护混凝土和砖石结构中的结构和非结构元件。包括四项主要任务；i) 材料研究，以研究 UHPC 改造的高应变行为和粘结响应，ii) UHPC 护套在混凝土建筑/桥梁柱中的应用，iii) UHPC 覆盖层在砖石墙中的应用； iv) 开发用于预测 UHPC 改造爆炸响应的分析模型 预计该研究计划将导致制定最佳实践指南和 CSA 标准规定。加拿大建筑业。