HPFL加固RC圆柱抗震性能试验研究

An Experimental Study on the Seismic Behavior of RC Cylinders Strengthened by High Performance Ferrocement Laminates

在轴力恒定和水平反复荷载作用下,对4根RC圆柱受力性能进行试验研究,证明了用高性能水泥复合砂浆钢筋网薄层(HPFL)加固RC圆柱,可以提高其抗震性能。通过对柱混凝土危险区段横向网筋形成的强约束和对纵向网筋的锚固,可使柱的抗震承载力和抗震延性提升,总耗能能力增长。具体地,对于卸轴力的一次受力加固柱,HPFL比原混凝土柱应变滞后的现象并不显著,使柱抗震承载力明显提高;对于不卸轴力的二次受力加固柱与不卸轴力且有震损的二次受力加固柱,尽管HPFL应变滞后原柱混凝土的现象依次加重,但由于加固层的延迟工作以及在塑性铰区逐步发挥作用的强约束机制使塑性铰转动能力增强,从而使柱延性有了依次增大的改善,而且震损加固柱已呈下降趋势的P-Δ骨架曲线回升,HPFL可使加固圆柱纵、横向裂缝形态明显改善。

An experimental test has been conducted on the seismic behavior of four RC cylinders under the action of constant axial force and repeated horizontal loads,which verifies an improvement in the seismic performance of RC cylinders strengthened with HPFL.The seismic bearing capacity and ductility of the column can be improved and the total energy dissipation capacity can be increased by the strong constraint on the transverse reinforcement of the column concrete danger section and the anchorage of the longitudinal reinforcement.Specifically,the strain of HPFL is not significant compared with that of the original cylinders for the primary reinforcement columns under unloading axial force,which improves the seismic bearing capacity of columns significantly.For the secondary stressed columns without axial force and the secondary stressed columns without axial force and seismic damage,although the HPFL strain lags behind the original column concrete phenomenon,the delay of the reinforcement layer and the strong restraining mechanism of the plastic hinge zone gradually exerts the effect of increasing the rotation ability of the plastic hinge,so that the column ductility is improved sequentially.Meanwhile,the P-Δ skeleton curve of the damaged column shows a downward trend,with the HPFL strengthened,verifying the conclusion that HPFL can obviously improve the longitudinal and transverse crack morphology of the reinforced cylinder.