(1 湖南大学土木工程学院，长沙 410082； 2 湘潭大学土木工程与力学学院，湘潭 411105)
［摘要］通过4根聚丙烯纤维砂浆钢筋网加固受弯足尺RC梁的二次受力试验，研究加固梁不同破坏特征和界限配筋率情况。试验表明：加固配筋率对加固梁的受弯承载力和变形性能有较大的影响，改变加固配筋率，加固梁分别呈现出受弯适筋破坏、界限破坏和超筋剥离破坏的特征。适筋破坏时，加固梁的屈服荷载和极限荷载提高幅度随加固配筋率的提高而增大；剥离破坏时，极限荷载提高幅度随加固配筋率的提高反而下降，加固梁的变形能力也显著下降。在试验和分析的基础上，给出了加固梁界限配筋率的确定方法。
［关键词］聚丙烯纤维砂浆；加固配筋率；界限配筋率；剥离破坏
Experimental study on critical reinforcement ratio of flexural RC beams strengthened with Polypropylene Fibre Mortar
Bu Liangtao1, Li Hongbing1, Zhou Jing2（1 Civil Engineering College, Hunan University, Changsha 410082, China; 2 Civil Engineering & Mechanics College, Xiangtan University, Xiangtan 411105, China)
Abstract:Four full-size RC beams strengthened with Polypropylene Fibre Mortar were tested to investigate the failure characteristic and critical reinforcement ratio. The results indicate that the strengthened reinforcement ratio plays an important role in increasing the loadbearing capacity and distortion capacity. The ratio of the strengthening bar was varied, three kinds of failure behaviors bending failure, balance failure and edge debonding peeling failure were observed. The yield and limit loads of bending failure beams tend to grow with the increase of the strengthening bar area, however, edge debonding peeling failure beams tend to descend with the increase of the strengthening bar area and the deformation performance of the strengthened beams markedly reduces. Based on the experimental results and analysis, the determination method of critical reinforcement ratio was obtained.
Keywords:Polypropylene Fibre Mortar; strengthened reinforcement ratio; critical reinforcement ratio; edge debonding peeling failure
湖南省交通厅科研基金（200412），湖南省科技厅科技重点科研基金(05SK2010, 2006GK3103)。
作者简介：卜良桃，博士, 教授，Email：plt63@126.com。
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