CFRP约束损伤钢筋混凝土的轴压性能

Axial Compression Behavior of CFRP-confined Damaged Reinforced Concrete

设计了29个不同配箍率、CFRP层数及预损伤水准的钢筋混凝土(RC)方柱试件进行轴压试验;通过对试验数据的回归分析,提出了CFRP约束损伤钢筋混凝土的受压本构模型.结果表明:外包CFRP能有效地恢复甚至提高损伤钢筋混凝土的轴压强度及延性,其加固效果随CFRP用量的增加及预损伤水准的降低更为显著;损伤钢筋混凝土的弹性模量则随着损伤水准的增大而减少;反复荷载作用下C,FRP约束损伤钢筋混凝土的应力-应变曲线的包络线与单调荷载作用下的应力-应变曲线基本重合;文中提出的模型预测与试验数据高度吻合.

A total of 29 square reinforced concrete(RC) columns with different amounts of internal steel reinforcement and of externally wrapped CFRP as well as pre-damage levels,were designed and tested under axial compression.On the basis of regression analysis of the test results,a stress-strain model for CFRP-confined damaged reinforced concrete under axial compression was proposed.The test results show that CFRP wrapping is effective in restoring or even enhancing the compressive strength and the strain capacity of damaged reinforced concrete.Both the compressive strength and the ultimate strain of CFRP-confined damaged reinforced concrete increase with the increase of the quantities of CFRP and the decrease of pre-damage levels,while the initial elastic modulus decreases with the increase of pre-damage levels.Under cyclic loading,the envelope curve of cyclic stress-strain response of CFRP-confined damaged reinforced concrete under axial compression coincides with the monotonic counterpart.The prediction provided by the proposed model agrees well with the test results.