反复荷载作用下复合加固损伤混凝土柱性能的试验研究

Experimental Investigation on the Damaged Reinforced Concrete Column Composited Strengthened under Cyclic Loading

针对柱身已开裂、柱底固定端已形成塑性铰的严重损伤的3根钢筋混凝土柱,采用沿柱高粘贴CFRP布箍和底部固定端反贴角钢的共同加固新方法,可以达到既加固钢筋混凝土柱身,又使柱底重新成为固定端的目的.然后,对已进行加固的3根柱子进行模拟地震作用的水平低周反复荷载试验,研究二者复合加固严重损伤的混凝土柱的性能.基于试验结果,分析了加固柱的延性、刚度和承载力退化规律以及加固材料(角钢和CFRP布箍)的受力性能.结果表明,CFRP布箍可以有效地约束混凝土的横向膨胀;角钢的竖向钢板在柱底部作用最大,均可以达到屈服强度,但距离底部越远的钢板的应力大幅度降低;水平钢板破坏时是压曲破坏.

The new method that composited strengthened by CFRP hoops along the columns and angle steels at the end of the columns was advanced for three seriously damaged reinforced concrete columns with cracking and the end forming plastic hinges. The reinforced concrete column was strengthened and column end was formed fixed end. The experiments were done under low-cyclic and repeated load for the strengthened columns. The performances of the strengthened columns about different limb lengths of angle steel were studied. Based on test results, the ductility,stiffness and reduction capacity of the specimens were analyzed, strengthened CFRP hoops and steel＇s hysteresis curves of the sample were drawn out. The results showed that the strengthened CFRP hoops could constrain expansion of concrete columns, and end vertical steels were mainly tensioned yield and horizontal steels were compressed yield.