FRP加固钢筋混凝土柱经历模拟地震作用后的残余性能试验研究

本文对8根大比例的FRP加固钢筋混凝土桥柱模型在轴压比为0.2的恒定轴压力下进行拟静力试验,再对其中5根试验柱在经历有限的地震作用后进行长期荷载作用下的轴压试验。试验表明,FRP加固柱的徐变变形远小于对比柱的徐变变形;带损伤的加固柱在长期荷载作用下的变形发展受加固柱的损伤程度和持荷大小的控制,并与FRP的弹性模量有关;在试验条件下,带损伤的加固柱长期轴向变形呈稳定态势。采用AEMM和F ind ley模型为基础,考虑损伤程度、密封状态、三向应力状态和应力重分布等因素的影响,建立了损伤加固柱的徐变计算模型,并进行了验证。分析表明,损伤对加固柱的徐变发展和徐变破坏时限有显著影响。

Long-term residual behavior of FRP retrofitted RC columns after damaged by simulated earthquake loading

This paper addressed residual seismic behavior of reinforced concrete(RC) columns retrofitted with fiber-reinforced plastic(FRP).Eight model columns were tested under cyclic lateral force with a constant load equal to 20% of the column gross axial load capacity.Five of them were continued to be tested under long-term axial loading.The deformation of retrofitted columns under long-term axial loading depended on the previous damage intensity and the modulus of FRP.Under the testing condition of this study,the long-term axial deformation of retrofitted column tends to be stable.Analytical studies were carried out by using the age-adjusted effective modulus method for creep of concrete,combined with the Findley′s power law function for creep of FRP jacket.The model took the following factors into consideration,namely the effects of damaged degree of earthquake,sealed concrete,multi-axial state of stresses and stress re-distribution.The model was verified against the long-term test in this paper.The analytical results show that degree of damage has important effect on creep and creep rupture life expectancy.