Seismic Performance of FRP-Reinforced Concrete Columns

钢筋锈蚀问题是限制钢筋混凝土结构使用寿命的最大因素。在某些情况下，维修成本可能是初始成本的两倍。在混凝土结构中使用纤维增强聚合物（FRP）钢筋是解决钢筋劣化问题的一个很有前途的方法。玻璃钢材料通常比传统钢材具有许多优点，例如重量轻和耐腐蚀性。然而，它们具有线性弹性行为直到失效，不同的粘结特性，在压缩和剪切应力下的低强度，以及与钢相比相对较低的弹性模量。FRP材料的这些特性使得FRP-RC结构的行为不同于用钢加固的相应结构，并引起人们对FRP-RC结构的延性性能、抗剪能力和完整性的关注，特别是在地震荷载下。桥梁和停车场是混凝土基础设施的主要例子，这些基础设施承受着恶劣的环境和荷载条件，其中FRP加固的应用具有很大的潜力。钢筋混凝土柱是此类结构中的主要结构元件，并且在地震（地震）事件的情况下是最关键的构件。然而，由于关于这些柱的地震效应的可用数据非常有限，因此缺乏设计指南。这项研究工作试图部分填补这一空白。本文将对FRP-RC柱在模拟地震荷载作用下的结构性能和极限承载力进行试验和分析研究。实验工作将在全尺寸柱样本上进行，该样本代表基础水平上方柱的最关键部分。然而，将使用非线性有限元分析进行分析建模，以模拟柱中应力和应变的复杂分布，同时考虑FRP筋的力学性能和粘结特性。这项研究工作的结果将被制定为变形和整体柱的设计方程和准则。此外，这项拟议的研究计划将有助于在混凝土结构先进复合材料领域对四名研究生（博士和硕士）进行独特和高度专业化的培训，以满足加拿大结构工程界对HQP日益增长的需求。通过避免钢腐蚀，更好地了解结构行为，并为这些主要元素制定设计指南，这项研究将导致新结构的性能提高，更好的耐久性和降低生命周期成本，这将有利于交通部，交通部和公共工程部等基础设施所有者。

The corrosion problem of steel reinforcing bars is the greatest factor in limiting the life expectancy of reinforced concrete (RC) structures. In some cases, the repair cost can be twice as high as the initial cost. One promising solution to the problems caused by deterioration of steel reinforcement is the use of the Fibre-Reinforced Polymer (FRP) reinforcing bars in concrete structures. FRP materials in general offer many advantages over conventional steel, such as light weight and corrosion-resistance. However, they have linear-elastic behaviour till failure, different bond characteristics, low strength under compression and shear stresses, and a relatively low modulus of elasticity compared to steel. These characteristics of FRP materials make the behaviour of FRP-RC structures different from their counterparts reinforced with steel and raise concerns regarding the ductility performance, shear capacity and integrity of FRP-RC structures, especially under seismic loads. Bridges and parking garages are prime examples of concrete infrastructure subjected to harsh environmental and loading conditions where the application of FRP reinforcement has high potential. Reinforced concrete columns are primary structural elements in such structures and the most critical members in case of a seismic (earthquake) event. However, design guidelines are lacking due to the very limited data available on the seismic effects on these columns. This research work is attempting to partially fill this gap. Experimental and analytical investigations on the structural performance and ultimate capacity of FRP-RC columns under seismic-simulated loading conditions will be carried out. The experimental work will be conducted on full-scale column specimens representing the most critical part of a column right above the foundation level. The analytical modelling, however, will be performed using nonlinear finite element analysis to model the complex distribution of stresses and strains in columns while considering the mechanical properties and bond characteristics of FRP bars. The results of this research work will be formulated into design equations and guidelines for deformable and integral columns. In addition, this proposed research program will contribute to the unique and highly specialized training of four graduate students (PhD & MSc) in the area of advanced composite materials for concrete structures fulfilling the increasing demand for HQP in Canada’s structural engineering community. By avoiding steel corrosion, better understanding the structural behaviour, and the development of design guidelines for such primary elements, this research will lead to new structures with improved performance, better durability and reduced life-cycle cost, which will benefit infrastructure owners such as Ministries of Transportation, Municipalities and Public Works.