体外预应力竖向张拉法加固RC梁挠度计算

对7根钢筋混凝土简支梁（2根对比梁、5根加固梁）进行加载试验，并通过试验数据，分析了不同张拉控制应力下各梁的挠度变化规律。体外预应力竖向张拉法加固混凝土梁能显著改善梁的受力和变形性能，不仅能抵消部分荷载在梁跨中的挠度，而且能在加固梁跨中产生反拱，反拱度随应力的增加而增加，能够较好地减少加固梁跨中挠度。体外预应力梁的挠度计算为外荷载产生的挠度减去预应力筋产生的反拱，计算值与试验值较吻合。

DEFLECTION CALCULATION ON REINFORCED CONCRETE BEAMS STRENGTHENED BY EXTERNALLY PRESTRESSING VERTICAL TENSIONING METHOD

In this paper, seven reinforced concrete beams （two contrast beams and five externally reinforced beams）were tested. The regularity of load-deflection under different tension stress were analyzed through experimental data. The experimental results showed that externally prestressing vertical tensioning method could significantly improve flexural and deformation performance of beams. The externally prestressing vertical tensioning method not only offset the deflection of the beams effected by partial load,but also produce the antiarch of reinforced beams in the midspan. The antiarch increases with stress, be able to well reduce the midspan deflection of the reinforced beam. The deflection calculation of externally prestressed beams is that the deflection produced by load minus the antiarch produced by prestressed reinforcement, and the calculated results coincide with the experiment results well.