炭纤维强化板及其加固混凝土梁的力学性能

Mechanical properties of CFRP and its reinforced concrete beams

  • 摘要: 为探寻涂胶对炭纤维布力学性能的影响 , 深入了解其加固混凝土结构的力学行为 , 对制备的炭纤维强化板(CFRP)及其加固混凝土梁 , 分别进行了轴向拉伸和预制裂缝四点弯曲加载实验。对比有胶与无胶纤维布拉伸实验 , 表明环氧树脂不仅粘接纤维布 , 对纤维布有保护作用 , 而且能够显著提高其拉伸强度。通过对加固混凝土梁的 FRP外贴应变片的加载过程进行电测跟踪测试 , 得到了材料结构损伤破坏过程曲线。由力学模型和曲线点拟合的最小二乘法 , 对 CFRP板所受轴力及混凝土的界面剪应力分布进行分析 , 得到轴力及剪应力分布。在载荷的变化过程中 , FRP与混凝土的界面逐渐脱粘 , 使得 FRP的应力集中程度降低 , 有时会出现应变回弹现象。

     

    Abstract: To investigate the effect of glue's adhesive on the mechanical properties of CFRP and its reinforced concrete structure mechanical behavior , the CFRP sheets and concrete beams were prefabricated , and the mechanical properties of them were investigated by the axial tension and four-point bending beams tests. The experiment compare of carbon cloth's tension strength with and without glue indicates that the epoxy resin can not only make the fiber adhesive united but also increase the tensile strength. The strain gauges were adhered on the surface of CFRP of a four-point bending concrete beam. With the electrometric method , the damage process curves of the materials were obtained. Through the mechanics analysis model and the least square method , the axis force and shear stress distributions of CFRP were analyzed , respectively. With the debonding of interface between FRP and concrete beam , the maximum value of tension stress of FRP reduces , thus a strain rebound phenomenon appears.

     

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