内嵌预应力螺旋肋钢丝加固混凝土梁受弯性能试验研究

采用内嵌预应力加固法张拉系统，提出开槽、加固和张拉螺旋肋钢丝、填胶的施工工艺，并在此基础上，进行了10个内嵌预应力螺旋肋钢丝加固混凝土梁试件的试验研究。结果表明，采用内嵌预应力螺旋肋钢丝加固法，能够较好地改善被加固钢筋混凝土梁的整体工作性能，大幅度提高其开裂荷载，对屈服荷载和极限荷载也有明显的改善。随加固量及预应力水平不同被加固梁开裂荷载提高幅度为72.6%~321.26%，屈服荷载提高幅度为6.19%~99.09%，极限荷载提高幅度为46.04%~135.27%，加固效果明显。该加固方法能够有效改善加固梁的延性和安全性能，梁试件刚度提高明显，对裂缝的产生和发展都有约束作用，具有良好的加固效果，同时螺旋肋钢丝的高强性能也得到了充分发挥。

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

This paper adopts near surface mounted prestressing helical rib steel wire system, using the process of slotting, reinforcing and tensioning helical rib steel wire, filling glue. An experimental study was conducted on 10 RC beams with near surface mounted prestressing helical rib steel wire. The experimental results indicate that this method can improve the overall performance of reinforced concrete beams. The first-crack load，flexural load，ultimate load are increased effectively. With various numbers of helical rib steel wire and prestressing levels，the first-crack load, flexural load and ultimate load can be increased by 72.6%-321.26%, 6.19%-99.09% and 46.04%-135.27% respectively. This strengthening method can effectively improve the ductility, safety performance and stiffness of reinforced concrete beam. The emergence and development of cracks can be restrained, and the high strength of helical rib steel wire can be fully used.