横向预应力钢套箍加固RC柱研究综述

在土木工程加固领域,对加固材料施加一定的预应力可有效约束裂缝开展,提高加固材料利用率,减小应力滞后效应,有效提高加固效果。采用横向预应力技术主动约束核心混凝土是提高加固钢筋混凝土柱力学性能和变形性能的有效方法。该文简要回顾目前国内外采用横向预应力技术加固钢筋混凝土柱的研究现状,重点介绍华侨大学提出的新型预应力钢套箍(Prestressed Steel Jacket, 简称PSJ)加固钢筋混凝土柱加固技术,及采用PSJ技术加固钢筋混凝土柱所开展的抗震性能、抗剪性能和轴压性能等方面研究工作进展。研究结果表明,采用PSJ技术可有效改善钢筋混凝土柱的抗震性能,提高钢筋混凝土柱的抗剪承载力、轴压承载力和变形能力等;实现钢套箍预应力施加及精确控制,钢套箍安装便捷,加固后不改变原构件截面尺寸和刚度,不影响原结构地震剪力分配,在混凝土结构加固领域具有广阔的应用前景。最后对PSJ加固技术今后研究发展方向提出建议和展望。

PRESTRESSED STEEL JACKET FOR RETROFITTING REINFORCEMENT CONCRETE COLUMN

In the field of structural strengthening, applying prestress to strengthening materials could be effective in constraining crack development, improving the utilization of materials, diminishing or eliminating leg-stress effect and enhancing the strengthening effect. Active constraint by prestress technology can significantly improve the mechanical and deformation properties of reinforcement concrete(RC) columns. In this paper, recent developments in the field of RC column strengthening using active constraint were briefly reviewed. Particular emphasis is taken to the new retrofit technique of RC column using prestressed steel jacket(PSJ), developed and realized in the structural laboratory in Huaqiao University. The researches, such as the aseismic performance, shear performance and axial compression performance of retrofitted RC columns using PSJ, were introduced. The results show that PSJ can effectively improve the aseismic performance, and enhance the shear strength, axial bearing capacity and deformation property. The prestress of steel jacket can be applied easily and controlled precisely. After strengthened, the section size and the original stiffness of components are not changed, which will not influence the aseismic shear distribution of an original structure. These results are encouraging, and the retrofit technique could be broadly applied in the field of structural strengthening. Finally, the outlook and suggestion about the PSJ retrofit technology were proposed.