混杂纤维布加固钢筋混凝土梁抗弯性能试验及理论研究  

EXPERIMENTAL AND THEORETICAL RESEARCH ON FLEXRUAL PERFORMANCE OF RC BEAMS STRENGTHENED WITH HYBRID FIBER SHEETS

作　　者：邓宗才[1] 李建辉[1] 

机构地区：[1]北京工业大学建筑工程学院,北京100124

出　　处：《工程力学》2009年第2期115-123,130,共10页Engineering Mechanics

基　　金：国家自然科学基金项目(50678011);北京市自然科学基金项目(8082002);教育部博士点基金项目(200800050012)

摘　　要：该文提出了碳/芳纶/玻璃三种纤维混杂思路,高强、高弹模碳纤维提高承载能力,高延伸率玻璃纤维改善延性,而芳纶纤维使应力从碳纤维向玻璃纤维平稳转移。通过对11根钢筋混凝土梁的抗弯试验,研究了不同混杂方式、混杂结构、纤维布层数对梁抗弯性能的影响。结果表明:如果应力转移不平稳,混杂纤维布将与混凝土发生局部剥离,导致混杂纤维布加固效果降低;在相同纤维布层数条件下,与单一碳纤维布加固梁相比,碳/芳纶/玻璃层间混杂纤维布加固梁的初裂、屈服、峰值和极限荷载分别降低了22%、12%、12%和16%,而位移延性系数提高了20%,表明碳/芳纶/玻璃层间混杂纤维布能够显著降低单一碳纤维布的脆性。在试验研究的基础上,采用弹塑性截面分析法计算了混杂纤维布加固梁的承载力,理论计算值与试验值吻合良好。An idea of hybrid composites containing carbon fiber, aramid fiber and glass fiber was proposed in this paper. Carbon fiber with high strength and high modulus was used to ensure the enhancement of bearing load, glass fiber with high rupture strains was used to achieve the ductile behavior, and the progressive stress transition in hybrid fiber sheets was realized by the use of aramid fiber. A series of 4-point bending experiments were carried out to investigate the effects of hybrid mode, hybrid structure and layer of fiber sheets on the flexural behavior of beams strengthened with hybrid fiber sheets. Results show that, if the stress in hybrid fiber sheets can＇t be transferred stably, the local debonding between hybrid fiber sheets and concrete will occur, resulting in the weakened hybrid effects; with the same total layers of fiber sheets, the cracking load, yielding load, maximum load and ultimate load of RC beams strengthened with carbon/aramid/glass laminated hybrid fiber sheets are respectively 22%, 12%, 12% and 16% less than that of the RC beam strengthened with single carbon fiber sheets, while the displacement ductility index increases 20%, indicating that the carbon/aramid/glass hybrid fiber sheets can amend significantly the brittleness of single carbon fiber sheets. Based on the experimental research, an elastoplastic section analysis method is conducted to predict the bearing capacity of RC beams strengthened with hybrid fiber sheets, the results from the theoretical predictions and the experiment agree well.

关 键 词：纤维增强聚合物 混杂 芳纶纤维 梁 抗弯性能 延性 

分 类 号：TU375.1[建筑科学—结构工程]