混杂FRP加固腐蚀混凝土柱恢复力模型研究

STUDY ON RESTORING FORCE MODEL OF RC CORRODED COLUMNS STRENGTHENED WITH HYBRID FRP

研究外贴纤维增强聚合物(Fiber Reinforced Polymer FRP)、钢筋腐蚀对混凝土柱恢复力特性的影响,是研究服役混凝土结构抗震性能的重要内容。该文根据混杂FRP加固腐蚀混凝土柱抗震性能试验结果,在完好钢筋混凝土构件的截面分析和Clough滞回规则的基础上,提出了混杂FRP加固腐蚀混凝土柱恢复力模型及其骨架曲线的确定方法。研究表明:对于受腐蚀混凝土柱,由于腐蚀作用导致钢筋与混凝土的滑移明显增大,该文通过引入钢筋滑移模型对根据平截面假定计算的骨架曲线进行修正,可获得与试验吻合的结果。混杂FRP加固腐蚀混凝土柱仍可以采用现有的滞回规则(Clough滞回规则)建立恢复力模型,但需要对卸载刚度进行修正。这将为服役混凝土结构的地震反应分析与抗震可靠性评估提供依据。

The effect of FRP and reinforcement corrosion on the restoring characteristic of RC columns is a key issue in the seismic performance of existing RC structures. According to the experimental results, methods to determine the restoring force and skeleton curve of RC corroded columns strengthened with hybrid FRP were presented in this paper based on the cross-section analysis of undamaged RC element and Clough hysteresis rule. Results show that the skeleton curve calculated using the linear plane assumption with modification by bar-slip model can still be used as the skeleton curve of RC corroded columns strengthened with hybrid FRP, and good agreement between the calculated curve and the test result was obtained. The restoring force model for RC corroded columns strengthened with hybrid FRP can be established using Clough hysteresis rule with a modification for unloading stiffness. The basic theory for seismic damage rehabilitation and evaluation of existing RC structures were presented finally.