Performance evaluation of High-Performance Fibre-Reinforced Cementitious Composite slab-column connections

随着全球建筑业的不断加速增长，结构工程师可以通过为可持续和有弹性的结构引入新技术和材料来帮助保护我们的资源，同时减少建筑的碳足迹，从而成为环境的负责任的管家。根据加拿大国家气候变化政策，通过碳税或可交易的碳排放许可制度，水泥的成本将在未来几年大幅增加。为了减少水泥产量，一个潜在的解决方案是在结构中使用高性能纤维增强水泥复合材料（hpfrcc），通过用粉煤灰部分替代波特兰水泥来提高可持续性。hpfrcc是一种相对较新的创新材料，它可以抵抗大的拉伸和剪切力，在直接拉伸下表现出应变硬化，增加韧性和延性，裂缝控制，在动态影响下的性能增强，与传统混凝土相比，具有高能量吸收能力。尽管HPFRCC的力学性能已经得到了研究，并且文献记录相对较好，但仍需要研究开发模型和建立设计指南，以便在关键基础设施中大规模使用HPFRCC。由于平板结构具有许多优点，在许多多层建筑中得到了广泛的应用，但其易受冲剪破坏的影响。在本研究计划中，将考虑一种新型HPFRCC，并对板-柱连接的冲剪性能进行研究。拟议的研究计划将考虑在连接处使用HPFRCC作为冲剪加固的替代方案。这项工作将首先评估HPFRCC的力学性能，然后进行新型板-柱连接的冲剪试验研究。在HPFRCC板中，受弯钢筋比的影响将被检查，考虑到潜在的钢筋减少，由于降低了腐蚀风险而带来的好处。同时，考虑重力诱导剪切对楼板旋转和漂移能力的影响，对所提出的高强度混凝土混凝土楼板的抗震性能进行了研究。最后，测试的HPFRCC板将使用先进的非线性有限元分析（FEA）进行分析，其中将考虑当前和新开发的塑性损伤模型。将进行混凝土性能、钢筋性能和位置、不平衡力矩和支撑几何形状对平混凝土板冲剪强度的影响的参数化研究。该研究项目旨在通过结合学徒制、导师制和令人兴奋和严谨的研究环境，培养和激励高素质人才（HQP）。

As the growth of global construction keeps accelerating, structural engineers can serve as responsible stewards of the environment by introducing new technologies and materials for sustainable and resilient structures that help to preserve our resources while reducing the carbon foot print of construction. Based on the Canadian National Climate Change Policy, the cost of cement will increase dramatically in the coming years through carbon tax or a system of tradeable carbon emissions permits. In order to reduce cement production, a potential solution is to use High-Performance Fibre-Reinforced Cementitious Composites (HPFRCCs) in structures to increase sustainability through partial replacement of Portland Cement with fly ash. HPFRCCs are relatively new and innovative materials that resist large tensile and shear forces showing strain hardening in direct tension, increased toughness and ductility, crack control, enhanced performance in case of dynamic effects, and high-energy absorption capacity when compared to conventional concrete. Whereas the mechanical properties of HPFRCCs have been studied and are relatively well documented, research is required to develop models and establish design guidelines to enable large scale HPFRCC use in critical infrastructure. Flat slabs are widely used in many multistory buildings because of the many advantages that they provide, however, they are susceptible to punching shear failure. In this research program, a novel HPFRCC will be considered and the punching shear behaviour of slab-column connections will be investigated. The proposed research program will consider HPFRCC at the connections as an alternative for punching shear reinforcement. This work will first evaluate the mechanical properties of HPFRCC and then undertake an experimental investigation of punching shear in novel slab-column connections. In HPFRCC slabs the effect of the flexural reinforcement ratio will be examined considering potential reductions in steel reinforcement leading to benefits due to the reduced risk of corrosion. At the same time, the seismic performance of the proposed HPFRCC slabs will be examined considering the effect of gravity-induced shear on the rotation and drift capacity. Finally, the tested HPFRCC slabs will be analyzed using advanced nonlinear finite element analysis (FEA), where current and newly developed plasticity-damaged models will be considered. Parametric studies on the effects of concrete properties, reinforcement properties and placement, unbalanced moments, and support geometry on the punching shear strength of flat concrete slabs will be undertaken. This research program is designed to foster and inspire the training of highly qualified personnel (HQP) over a five year period through a combination of apprenticeship, mentorship and exposure to an exciting and rigorous research environment.