Punching Shear Behaviour of FRP-Reinforced Concrete Slab-Column Connections

使用非腐蚀性纤维增强聚合物（FRP）钢筋来加固在恶劣环境中建造的混凝土结构，例如桥梁和停车场，有利于避免代价高昂的钢筋腐蚀问题。在北美，大量的停车场结构和工业建筑使用平板系统，其中混凝土板直接支撑在柱上。板柱节点是此类结构体系中最关键的节点，其冲切应力最大。冲剪破坏通常是脆性的、突然的和灾难性的，应该避免。由于FRP筋具有线性弹性行为，直到失效，刚度低，抗压强度降低，因此当使用FRP筋时，特别是在地震荷载下，人们担心这种接头的延性性能，抗剪能力和完整性。关于这一主题的数据非常有限或没有。 本研究计划调查FRP钢筋混凝土板柱连接的行为。拟议的工作分为四个项目，将由四名研究生（2博士）进行。2 M. S.）。每个项目有两个阶段：实验和分析。实验工作将在全尺寸板柱试件上进行，包括所有三种类型：内部连接、边缘连接和角连接。分析阶段包括非线性有限元建模，考虑柱附近板中应力和应变的复杂分布以及FRP筋的力学和粘结特性。该模型将根据实验结果进行验证，然后用于运行参数研究，以调查已知影响此类连接行为的广泛关键参数。试验结果将被公式化为可变形和整体板柱连接的设计方程和指南。通过避免钢腐蚀和更好地了解这些元素的结构行为，这项研究导致新的结构具有更好的性能，更好的耐久性和降低的生命周期成本。

The use of the non-corrodible fibre reinforced polymer (FRP) bars to reinforce concrete structures built in harsh environments, such as bridges and parking garages is beneficial to avoid the costly steel-corrosion problems. In North America, a large number of parking structures and industrial buildings is constructed using flat plate system in which concrete slabs are directly supported on columns. The most critical element in such structural system is the slab-column connection where punching shear stresses are the largest. Punching shear failures are usually brittle, sudden and catastrophic in nature and should be avoided. Since FRP bars have linear-elastic behaviour till failure with low stiffness and reduced compressive strength, there are concerns regarding the ductility performance, shear capacity and the integrity of such joints when FRP bars are used, especially under seismic loads. Very limited to no data is available on that topic. This research program investigates the behaviour of FRP-reinforced concrete slab-column connections. The proposed work is divided into four projects, which will be conducted by four graduate students (2 Ph.D. and 2 M.Sc.). Each project has two phases; experimental and analytical. The experimental work will be conducted on full-scale slab-column specimens covering all three types; interior, edge and corner connections. While the analytical phase includes nonlinear finite element modelling considering the complex distribution of stresses and strains in the slab near columns as well as the mechanical and bond characteristics of FRP bars. This model will be verified against experimental results then used to run parametric studies to investigate a wide range of key parameters known to affect the behaviour of such connections. The test results will be formulated into design equations and guidelines for deformable and integral slab-column connections. By avoiding steel-corrosion and better understanding the structural behaviour of such elements, this research leads to new structures with improved performance, better durability and reduced life-cycle cost.