Modern Concrete Structures: Modelling and Assessment

钢筋混凝土结构包括加拿大的大部分关键基础设施，从桥梁到核电站结构，医院到多层建筑。这一基础设施正处于成熟阶段，许多结构已经老化，需要维修。在某些情况下，重要的混凝土建筑物和桥梁由于若干因素，但主要是由于在其使用寿命期间维护不足，很容易无法使用，甚至发生灾难性故障。由于政府目前面临严重的经济限制，以及需要维修的混凝土结构缺陷高达数千亿美元，工程师需要先进的评估工具。这些工具将使他们能够评估当前结构的安全性和适用性，决定哪些需要维修，确定最经济有效的维修方法，并适当模拟采用新的创新材料的结构的性能。*** 合理可靠的手段，数值模拟传统的混凝土结构在良好的维修建立。多伦多大学以前对这一最新技术做出了重大贡献，制定了钢筋混凝土的简单合理的行为模型（例如，修正的压缩场理论），并将这些模型实现到高级非线性有限元分析（NLFEA）软件中（例如，Vector程序套件）。目前拟议的研究旨在扩展本构模型和分析程序，使现代混凝土结构的建模和评估，特别是那些在各种状态的损坏，恶化或缺陷，以及那些建造或修复新的创新材料。因此，调查计划在五个关键领域的利益：超高性能纤维增强混凝土（UHPFRC）;木材-混凝土复合材料（TCC）系统;钢-混凝土复合材料（SCC）系统;建模和修复恶化或腐蚀的结构;和建模和修复碱骨料反应（AAR）影响的结构。拟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。 拟议研究的预期成果和好处有两个方面：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。以及ii）分析程序将发展到一个水平，使其成为有用的设计办公室工具，适用于当今加拿大和其他地方的设计工程师所面临的各种问题。因此，拟议的研究将有助于设计或恢复技术和经济上可行的现代混凝土结构，这些结构安全，耐用和有效。

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.*****