FRP片材加固的钢筋混凝土梁短期刚度试验与理论研究  

Experimental and theoretical research on short-term stiffness of reinforced concrete beams strengthened with FRP sheets

作　　者：陈绪军[1] 李华锋[1] 朱晓娥[1] 

机构地区：[1]九江学院土木工程与城市建设学院

出　　处：《建筑结构学报》2018年第1期146-152,共7页Journal of Building Structures

基　　金：江西省自然科学基金项目(20142BAB216004);江西省教育厅青年科学基金项目(GJJ13712)

摘　　要：通过4根未加固钢筋混凝土梁和10根玄武岩纤维增强复合材料（BFRP）布和碳纤维增强复合材料（CFRP）布加固钢筋混凝土梁的静载受弯试验,研究了纤维增强复合材料（FRP）片材加固梁的挠度和刚度变化,以及FRP粘贴层数、FRP强度和混凝土强度、剪跨对加固梁挠度和刚度的影响。研究结果表明：FRP片材能有效抑制梁裂缝的扩展,提高梁的抗弯刚度,减小梁跨中挠度。基于刚度解析法,将FRP片材换算为受拉钢筋,建立了FRP片材加固梁的短期抗弯刚度计算公式,当FRP加固量为零时,该公式可退化为GB 50010—2010《混凝土结构设计规范》中未加固梁的抗弯刚度计算式,所建立的FRP片材加固梁抗弯刚度计算式的适用范围有所加大。通过试验数据,对所建立的抗弯刚度计算公式的精度进行了验证,结果表明,理论公式计算值与试验值吻合良好,可为FRP片材加固的钢筋混凝土梁理论分析和设计提供参考。The flexural tests were conducted on four non-strengthened reinforced concrete （RC） beams and ten RC beams strengthened with basalt fiber reinforced plastics （BFRP） cloth and carbon fiber reinforced plastics （CFRP） cloth under static load, and the variations of deflection and stiffness of RC beams strengthened with fiber reinforced plastics （FRP） sheets were studied. The influences of FRP layers, FRP strength, concrete strength and shear span on the deflection and stiffness of strengthened beams were investigated. The results show that FRP sheets can effectively inhibit the expansion of beam cracks, improve the bending stiffness of beams, and reduce the mid-span deflection of beams. Based on the stiffness analytical method, by transforming FRP sheet into tensile reinforcement, the short-term flexural stiffness formula was proposed. When the area of FRP sheets is zero, the stiffness formula of strengthened RC beams can be simplified to the stiffness formula of non-strengthened RC beams given in the GB 50010--2010 ＇ Code for design of concrete structures＇ , and the scope for the application of the formula is broadened. The accuracy of the proposed formulas of flexural stiffness is verified by the experimental results of this paper and others. The results show that the calculated values show a good agreement with the experimental values, which can be used for flexural theoretical analysis and design for FRP-strengthened RC beams.

关 键 词：钢筋混凝土梁 FRP片材 加固 静载试验 短期刚度 挠度 

分 类 号：TU375.103[建筑科学—结构工程]