玻璃纤维聚合物约束混凝土柱轴压比限值研究

对采用外粘玻璃纤维布加固震损柱进行低周反复荷载试验 ,研究其力学性能。试验结果表明 :无论轴压比的高低 ,加固后柱的承载力和位移延性都有了不同程度的提高和改善 ,高轴压比柱的效果更加明显 ,加固前为小偏压破坏的柱 ,加固后变成了大偏压破坏 ,变形性能和耗能能力显著提高。基于试验结果和约束混凝土的计算分析理论 ,导出了玻璃纤维聚合物加固柱的轴压比限值。计算结果和试验结果均表明 ,加固后柱的轴压比限值可予以适当放宽。

Investigation on the Limit Values of Axial Compressive Ratio for RC Columns Confined with GFRP

The effectiveness of bonding GFRP sheets to retrofit reinforced concrete columns for enhancing their mechanical property was described. Eleven reinforced concrete columns were tested under cyclic lateral load and constant axial load. Test results show that the bearing capacity and displacement ductility of retrofitted columns are improved uncoordinatedly whether the value of axial compressive ratio is higher or lower. The higher the axial compressive ratio of RC column, the larger the effectiveness is. Before strengthening, the failure mode of the highest axial compressive ratio column is brittle failure, as large eccentric compression failure; but strengthened with GFRP, the failure mode turns into ductile fracture, as little eccentric compression failure. The strength, displacement and energy dissipating capacity are improved significantly. Based on the reported test results and confined concrete theory, the limit values of axial compressive ratio for columns strengthened by GFRP were derived. The test results and calculation results show that the limit values of axial compressive ratio for strengthened columns can be enlarged properly.