低速冲击下高强钢绞线网-高性能砂浆加固钢筋混凝土梁试验研究

Experimental Research on RC Beams Strengthened with High Strength Steel Wire Mesh and High Performance Mortar under Low Velocity Impact

研究了高强钢绞线网-高性能砂浆加固钢筋混凝土梁的抗低速冲击性能,利用落锤冲击试验法对4根简支钢筋混凝土梁进行对比试验研究,其中1根为普通梁,3根为加固梁,通过分析加固前后梁的破坏形态,结合挠度变化、钢筋的应变以及加速度的时程曲线,对比得到了钢筋混凝土梁加固后的抗冲击性能。研究结果表明:加固后钢筋混凝土梁的抗冲击能力显著提高,钢绞线和砂浆作为外加层,不仅增加了梁的抗弯剪能力和刚度,提高了结构的耗能能力,而且限制了裂缝的发展,使梁的整体性和延性更好;在相同冲击作用下,钢绞线直径的增加能适当提高结构的抗冲击性能。

This paper studies the impact resistance properties of RC beams strengthened with high strength steel wire mesh and high performance mortar under low velocity impact. Drop hammer impact test is conducted on 4 simply supported RC beams, including 1 RC beam and 3 strengthened RC beams. Through analyzing the failure pattern and the curves of deflection, strain and acceleration of steel, the impact resistance before and after strengthening are studied. The results show that the impact resistance properties of the RC beams is highly improved, the high strength steel wire mesh and high performance mortar as the strengthening layer not only make a contribution to improve the shear-resistance,bend-resistance and rigidity and ability of energy dissipation, but also prevent the development of cracks and increase the ductility of RC beams. Under the same impact, increasing the diameter of the steel wire mesh could improve the impact resistance of the structures.