内嵌螺旋肋钢丝抗弯加固混凝土梁试验研究

Experimental study on flexural strengthening of RC beams with near surface mounted helical rib steel wire

为探讨更为有效的混凝土梁加固方法,通过7根梁试件的静力加载试验,对内嵌螺旋肋钢丝加固混凝土梁的受力过程、抗弯承载力、裂缝和变形情况等进行较为系统的研究。结果表明:所有内嵌螺旋肋钢丝加固的混凝土梁没有出现类似外贴纤维片材加固构件的剥离破坏现象。与未加固梁相比,该加固方法能够显著提高被加固梁的极限承载力,且提高幅度随加固量的增加而增加,最多可达144.2%。加固梁破坏时的裂缝间距、最大裂缝宽度、挠度都较被加固梁小。加固梁的刚度有明显提高。研究成果为该新型加固技术在工程中应用提供了依据。

In order to develop an efficient strengthening method,seven beams strengthened with helical rib steel wire near-surface mounted （NSM） in sawed grooves in the concrete cover under monotonous loads are tested,and the ultimate capacity,cracks and deformation of reinforced concrete beams are systematically studied.Test results indicate that NSM helical rib steel wire can overcome the peeling of the strengthening material from externally bonded Fiber Reinforced Plastics laminates.Compared with non-strengthened beam,the strengthened beams can significantly improve its ultimate capacity,which increases with the number of helical rib steel wire,and the increase could be as much as 144.2%.The cracks space,width and the deformation capacity of strengthened beams is less than that of non-strengthened beam.The stiffness of strengthened beams is also improved.