Abstract

In recent years, for the reinforcement of concrete structures, fibre-reinforced polymers have been extensively employed, thus enhancing the structural properties of the reinforced materials. This paper presents a pre-stressing strengthening method for the confinement of large-scale circular concrete columns. The axial compressive behaviour of confined columns was tested and analysed. The experimental and analytical results indicated that the stiffness, ductility, and bearing capacity of reinforced concrete (RC) columns strengthened with pre-stressed carbon fibre-reinforced polymer (CFRP) composites were significantly higher than those of non-prestressed columns. A theoretical relationship between the peak strength and bearing capacity of large-scale RC columns actively confined by pre-stressed CFRP composites was proposed. A tri-linear stress-strain model for the actively confined large-scale concrete columns was presented and compared with the experimental results. Moreover, the model is sufficiently simple for use in design. The results of the proposed model were compared with the experimental results of small-scale columns, and the influence of size was found to be critical to the analysis of RC columns confined by pre-stressed CFRP composites.

摘要

近年来，在混凝土结构的加固中，纤维增强聚合物得到了广泛的应用，从而增强了增强材料的结构性能。本文提出了一种用于约束大型圆形混凝土柱的预应力加固方法。对受限柱的轴向压缩行为进行了测试和分析。实验和分析结果表明，用预应力碳纤维增强聚合物（CFRP）复合材料加固的钢筋混凝土（RC）柱的刚度、延性和承载力显着高于非预应力柱。提出了由预应力CFRP复合材料主动约束的大型RC柱的峰值强度与承载力之间的理论关系。提出了主动约束大型混凝土柱的三线应力应变模型，并与试验结果进行了比较。此外，该模型在设计中使用非常简单。将所提出模型的结果与小型柱的实验结果进行了比较，发现尺寸的影响对于由预应力 CFRP 复合材料约束的 RC 柱的分析至关重要。