【作者】 任伟；

【导师】 贺拴海；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2006， 博士

【摘要】 片材加固技术(粘贴钢板或纤维)，由于其材料的杰出力学性能及施工简便等特点，迅速成为国内外加固研究领域的热点。但是由于受到试验规模及资料共享问题的制约，目前所取得的研究成果，特别是试验成果还带有较大的片面性。本文作为编制《公路桥梁加固技术规范》中的片材加固方法的前期研究，首次以中国上世纪60～70年代修建的16m公路钢筋混凝土T梁桥为原型，以18片钢筋混凝土T梁室内缩尺模型试验和12对片材粘贴试验为基础，对片材加固混凝土T梁桥机理、设计方法进行了系统的研究，并提出了设计建议。 在片材与混凝土的粘贴试验中，分别对混凝土表面处理、片材数量及种类进行了研究。得出混凝土表面处理对粘贴效果影响显著；粘贴强度随片材数量的增大而提高；片材强度利用率随粘贴数量的增大而降低；钢板的粘贴效果比纤维的粘贴效果差等结论。 正截面加固试验中，分别对粘贴纤维、钢板对钢筋混凝土T梁正截面力学行为影响展开研究。粘贴片材后，梁的开裂荷载、屈服荷载及极限荷载均有所提高，其中极限荷载提高最为显著；承载力随粘贴片材数量的增加而提高，但并非线性提高；在有初始荷载的情况下，片材对屈服荷载的的影响较小，但是对极限荷载有一定影响；粘贴片材可以有效降低梁的挠度；混凝土开裂前，片材对提高梁的刚度贡献较小。而在带裂缝工作阶段，粘贴片材对提高梁刚度的作用显著；加固后梁的裂缝间距变小、数量变多、宽度变小；粘贴片材后T梁的延性明显低于未加固梁，而且片材越多，延性降低越多。 斜截面加固试验中，对片材粘贴方式、数量、是否锚固等展开研究。粘贴片材后，有锚固的加固方式能有效的提高梁的极限承载能力，而且承载能力随加固量的增大而增长；未采取锚固措施的加固方法，容易出现早期破坏，而且，粘贴片材越多，越容易发生早期破坏；粘贴片材可有效降低裂缝发展速度和减小裂缝宽度。 以试验为基础，结合理论分析，取得了以下创新性研究成果： 首次提出混凝土净保护层厚度对粘贴强度影响修正系数——目前的片材与混凝土界面性能研究，均立足于以素混凝土作为基材的粘贴试验基础之上。而在实际的片材加固中，由于受到梁边缘主筋对混凝土截面的消弱，浅层混凝土破坏均更多还原

【Abstract】 Sheet materials reinforcement technology (paste the steel plate or the fibre reinforced polymer), becomes the focus of strengthening the research field both at home and abroad rapidly as its outstanding mechanical property and handy construct etc. However, because of the restriction of experiment scale and the data share problem, the reported research fruits, especially the experiment achievements, have great one-sidedness problems. As research of strengthening method of sheet materials in" Code for strengthening highway bridges " in advance, basing on the experiments for 18 models of RC T-beams which model the real 16m T-beam bridges built in the 1960s in China for the first time and bonded experiments of 12 specimens, this paper have studies the mechanism, design methods of strengthening RC T-beam bridge and put forwards the suggestion of designing systematically.In the bonded experiments, the concrete surface treatment; sheet material quantity and material kind were studied. The conclusion as follows: the concrete surface processing has influence on the bond strength remarkably; Increased sheet material quantity does increase the bond strength; The material strength utilization will be lower as the sheet material quantity increased; The steel plate bond effect is worse than fiber’s etc.In the reinforcement experiments of right section, the influence of RC T-beam the mechanics behavior by FRP, steel plate was studied. The conclusion as follows: the cracking load, yielding load ,and limiting load are improved after reinforcing by sheet material and among them the improvement of limit loads is the most remarkable; the increasing of sheet material quantity improved bearing capacity but the effect is not linearly; In case of initial loading, sheet material puts smaller affect on yield load but has certain influence on the extreme limit load; Bonding sheet material can reduce the beam deflection effectively ;Before concrete fracture, sheet material put smaller contribution to sectional stiffness, however, after concrete fracture, the affect on sectional stiffness is outstanding; after reinforcement T-beam, fracture interval and width were diminish and quantity is increased; Ductility of T-beam is lower obviously after reinforcement, and the more quantity of material is increase, the more ductility is reduced.更多还原