Design and Evaluation of Critical Concrete Elements

关键混凝土构件的设计和评估

• 批准号: RGPIN-2019-04753
• 负责人: Mitchell, Denis
• 金额: $ 3.79万
• 依托单位: McGill 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=749509
• 关键词: Design; Evaluation; Critical; Concrete; Elements

The goal is to improve the responses of critical concrete elements that play a major role in the performance of bridge and building structures. This involves experimental and analytical research to predict the behavior of new elements as well as existing deficient structural elements. The overall objective is to improve the performance of Canada's infrastructure. Research will be carried out on the seismic performance of bridges to assess the recently developed seismic design provisions of the 2014 Canadian Highway Bridge Design Code. Reversed cyclic loading tests will be carried out on circular and rectangular columns to assess their shear resistance in regions of potential plastic hinges. The objective is to develop more rational design provisions for the shear resistance of typical bridge columns. This experimental study will also enable an assessment of the damage indicators that were adjusted in the 2019 proposed changes to the code. These damage indicators are key in assessing the performance of bridges. The response of deficient columns in existing bridge structures and analytical tools for predicting the extent of possible damage will be developed. The goal is to improve the safety of new bridges and older bridges that were designed before proper seismic design and detailing procedures were available. The evaluation and retrofit of deficient older bridges will be studied. There are many deficient bridges with poor reinforcing details and many are also suffering from concrete deterioration and from corrosion of reinforcing steel. Series of experiments will be carried out on elements with deficient details such as insufficient amount of crack control reinforcement and poor anchorage details of transverse reinforcement. Further investigations will be carried out on the use of drilled-in anchors used to provide shear reinforcement in thick slab concrete bridges to avoid shear failures and the effects of deterioration due to alkali-silica reactivity on the shear strength. Further experimental and analytical investigations will be carried out to study ways of preventing progressive collapse. Possible punching shear failures in parking garage structures affected by corrosion of the reinforcement and delamination will be studied further. Non-linear analyses of flat plate structures will examine the likelihood that an initial punching shear failure will progress into a progressive collapse if the code requirements for the application of structural integrity reinforcement are satisfied. Design and detailing requirements for achieving ductile columns when using ultra-high-strength concrete will be developed for use in high-rise construction. The confinement reinforcement must be effective to provide a ductile response after sudden cover spalling occurs. The use of fibre-reinforced high strength concrete in columns will be investigated to determine their blast resistance by testing the columns in a shock-tube testing facility.

目标是改善在桥梁和建筑结构的性能中起主要作用的关键混凝土元件的反应。这包括实验和分析研究，以预测新元素以及现有的缺陷结构元素的行为。总体目标是提高加拿大基础设施的性能。将对桥梁的抗震性能进行研究，以评估2014年加拿大公路桥梁设计规范中最近制定的抗震设计规定。将对圆形和矩形柱进行反向循环加载试验，以评估它们在潜在塑性铰区域的抗剪能力。目的是为典型桥梁柱的抗剪能力制定更合理的设计规定。这项实验研究还将对2019年拟议的规范变更中调整的损伤指标进行评估。这些损伤指标是评估桥梁性能的关键。将开发现有桥梁结构中缺陷柱的响应和预测可能损坏程度的分析工具。其目标是提高在适当的抗震设计和详细程序可用之前设计的新桥和老桥的安全性。对有缺陷的老桥进行评价和改造。有许多有缺陷的桥梁，其加固细节很差，许多桥梁还遭受混凝土变质和钢筋腐蚀的困扰。将对裂缝控制配筋量不足、横向配筋锚固细节差等细节不足的单元进行一系列试验。将进一步研究在厚板混凝土桥梁中使用钻孔锚来提供抗剪加固，以避免剪切破坏和碱-硅反应性对抗剪强度的恶化影响。将进行进一步的试验和分析研究，以研究防止渐进坍塌的方法。停车库结构受钢筋腐蚀和分层影响可能发生的冲剪破坏将进一步研究。平板结构的非线性分析将检验在满足结构完整性加固应用规范要求的情况下，最初的冲孔剪切破坏发展为渐进倒塌的可能性。在使用超高强度混凝土时实现延性柱的设计和详细要求将用于高层建筑。约束加固必须是有效的，以提供一个韧性响应后，突然覆盖剥落发生。将研究纤维增强高强混凝土在柱中的使用，通过在激波管试验装置中对柱进行测试来确定其抗震性。