CFRP约束高强混凝土梁跨中塑性铰延性性能研究

为提高高强混凝土梁延性性能,利用CFRP约束混凝土的性质,对跨中塑性铰区受CFRP环向缠绕的高强混凝土梁进行静载试验,考虑因素有包裹层数,包裹长度和配筋率。试验发现,包裹梁荷载位移曲线呈现4阶段变化,承载力在第3阶段平稳,在第4阶段缓慢上升。位移延性系数随包裹量增加而增大,但提高幅度会降低;随包裹长度增加而提高,剪跨区受包裹时,提高幅度提高显著;其提高幅度随配筋率的增大也显著提高,低配筋梁延性系数是其对比件的1.31倍,高配筋梁的延性系数是其对比件的3.34倍。拟合位移延性系数与各变量的公式,公式具有较好的准确度且偏于安全。

Experimental investigation of ductility of the reinforced high-strengthen concrete beams with plastic hinge CFRP-wrapped

In order to improve the ductility behavior of high strength concrete beams,with the advantage of the CFRP-Confined concrete,The static load tests on RC beams with plastic hinge at mid-span CFRP-Wrapped have been carried,selecting wrapped layers,wrapped length and reinforcement ratio as variables.Study finds the load-deflection curves of wrapped beams show four phase change,and load capacity in the third stage goes smoothly,in the fourth stage rise slowly.The displacement ductility coefficient increases when the wrapped layer increases,but the scale improves declines.And the coefficient rise when wrapped length grow,with an uptrend of the scale improves when shear span is wrapped;the improvement of beams with high reinforcement ratio is obvious than that with low reinforcement ratio.The coefficient of low reinforcement beam is 1.31 times than that of the control beams,but high reinforcement beam 3.34 times.Then an interrelated formula on the relationship between the displacement ductility coefficients is proposed,with good accuracy and safety-oriented.