Modern Concrete Structures: Modelling and Assessment

钢筋混凝土结构构成了加拿大的许多关键基础设施，从桥梁到核电站结构，从医院到多层建筑。这个基础设施处于成熟阶段，许多结构已经老化，需要维修。在某些情况下，由于许多因素，关键的混凝土建筑物和桥梁很容易失去使用，甚至是灾难性的失败，但主要是由于在其使用寿命期间维护不足。鉴于各国政府目前面临严重的经济约束，以及需要修复的混凝土结构缺陷库存高达数千亿美元，工程师们需要先进的评估工具。这些工具将使他们能够评估现有结构的安全性和可用性，决定哪些需要修复，确定最经济和有效的修复方法，并采用新的创新材料对结构的性能进行适当的建模。***已经建立了较为可靠的传统修复混凝土结构数值模拟方法。在此之前，多伦多大学为钢筋混凝土制定了简单而合理的行为模型（例如，修正压缩场理论），并将这些模型应用于先进的非线性有限元分析（NLFEA）软件（例如，VecTor套件程序），对这一最新技术做出了重大贡献。目前提出的研究旨在扩展本构模型和分析程序，以便对现代混凝土结构进行建模和评估，特别是那些处于各种损坏，退化或缺陷状态的结构，以及那些使用新型创新材料建造或修复的结构。因此，调查计划在五个关键领域：超高性能纤维增强混凝土（UHPFRC）；木-混凝土复合体系；钢-混凝土组合体系；模拟和修复老化或腐蚀的结构；碱集料反应（AAR）影响结构的建模和修复。建议的工作将是多方面的，包括理论制定，材料表征，软件开发和实验验证。***拟议研究的预期结果和效益是双重的：i)开发的分析模型将更全面，更准确地评估钢筋混凝土结构的性能；ii)分析程序将发展到一个水平，使它们可以成为有用的设计办公室工具，适用于今天加拿大和其他地方的设计工程师所面临的各种问题。因此，拟议的研究将促进技术和经济上可行的现代混凝土结构的设计或修复，这些结构是安全、耐用和高效的。*****

Reinforced concrete structures comprise much of the critical infrastructure in Canada, ranging from bridges to nuclear power plant structures, hospitals to multi-storey buildings. This infrastructure is at a mature stage, with many structures having aged and being in need of repair. In some cases, critical concrete buildings and bridges are vulnerable to loss of use or even catastrophic failure, owing to a number of factors but mostly due to inadequate maintenance over their lifetime. With governments currently facing severe economic constraints, and with the inventory of deficient concrete structures requiring repair amounting to hundreds of billions of dollars, engineers require advanced assessment tools. These tools would enable them to assess the safety and serviceability of current structures, decide which require repair, determine the most economical and effective means of repair, and properly model the performance of structures employing new innovative materials. ***     Reasonably reliable means of numerical simulation of traditional concrete structures in good repair are well established. Significant contributions towards this state-of-the-art were previously made at the University of Toronto with the formulation of simple and rational behavioural models for reinforced concrete (e.g., Modified Compression Field Theory), and the implementation of these models into advanced nonlinear finite element analysis (NLFEA) software (e.g., VecTor suite of programs). The current proposed research aims at extending the constitutive models and analysis procedures to enable the modelling and assessment of modern concrete structures, specifically those in various states of damage, deterioration or deficiency, and those constructed or repaired with new innovative materials. Accordingly, investigations are planned in five key areas of interest: ultra-high performance fibre reinforced concrete (UHPFRC); timber-concrete composite (TCC) systems; steel-concrete composite (SCC) systems; modeling and repair of deteriorated or corroded structures; and modeling and repair of alkali-aggregate reaction (AAR) affected structures. The proposed work will be multifaceted, encompassing theoretical formulation, material characterization, software development, and experimental verification.***     The anticipated outcomes and benefits of the proposed research are two-fold : i) The analytical models developed will be more encompassing and more accurate in their performance assessment of reinforced concrete structures.; and ii) The analysis programs will be developed to a level where they can be useful design office tools applicable to the types of problems faced by design engineers in Canada and elsewhere today. Thus, the proposed research will facilitate the design or restoration of technically- and economically-viable modern concrete structures that are safe, durable and efficient.*****