内嵌预应力螺旋肋钢丝加固RC梁承载力分析

Capacities of RC Beams with Prestressed Near-surface Mounted Helical Rib Steel Wire

在内嵌预应力螺旋肋钢丝加固混凝土梁试验研究基础上,给出了内嵌预应力螺旋肋钢丝抗弯加固混凝土梁消压弯矩、开裂弯矩等特征弯矩的计算公式,分析了预应力螺旋肋钢丝嵌入加固混凝土梁的弯曲破坏类型,推导了内嵌预应力螺旋肋钢丝加固混凝土梁弯曲破坏荷载计算公式,计算结果与试验结果吻合较好。研究结果为该新型技术更好地应用于实际工程提供了依据。

The various types of failures were summarized for concrete beams strengthened by near-surface mounted(NSM) prestressed helical rib steel wire based on the experiment.The calculating equations were presented for the characteristic bending moments,such as vanishing pre-compressive stress and cracking moments,of the strengthened beam.All possible strain combinations at ultimate limit state of flexure were analyzed for the composite section.The equations were derived to distinguish between two modes of flexural failure respectively due to fracture of helical rib steel wire and crushing of concrete.A set of equations are suggested for prediction of the corresponding ultimate strength.The applicability of the proposed equations was validated by good agreement of the analytical results with the measured values.