CFRP板加固混凝土梁受弯性能试验研究

发布时间：2018-01-06 18:15

本文关键词：CFRP板加固混凝土梁受弯性能试验研究　出处：《河北工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来，国民经济高速发展，交通量急速增长，在大量新公路桥梁建设的同时，由于年久失修，原设计标准低，不满足现行交通量与车载重量等原因，许多旧桥正逐渐成为病桥、危桥，严重阻碍了地区经济发展。因此，研究开发造价低，技术效果好的桥梁结构加固技术并投入使用对于推动我国的公路建设具有重要意义。 CFRP板加固桥梁结构是近几年才展开研究的一项加固技术，但CFRP板加固技术存在的一个关键问题是CFRP板的加固效率问题。本文设计了4根试验梁，其中1根为对比梁，3根为CFRP板的不同锚固方式的加固梁。针对目前使用的锚具制作成本高、不易加工、对CFRP板容易造成损伤且锚固力低等问题，本文设计了一种综合胶体粘结、钢板夹持、CFRP板穿孔的混合锚固方式的梁端锚固装置，并总结了CFRP板加固的施工工艺。深入分析了荷载值与混凝土应变、钢筋应变、CFRP板应变、试验梁挠度的关系，并研究了CFRP板的利用效率、试验梁的刚度和延性，最后对CFRP板的剥离理论进行了深入分析。研究结果表明，CFRP板加固混凝土梁的开裂荷载略有提高但不显著，但是对试验梁的屈服荷载和极限荷载却有30%左右的提高幅度。对于抑制钢筋应变和混凝土受压区应变的增长、提高CFRP板的强度利用率、限制裂缝宽度、减小裂缝间距方面，CFRP板的内嵌式锚固方式最为有效，其次是CFRP板的钢板压条锚固方式。所有加固梁的延性较对比梁都不同程度降低，U型箍锚固方式的加固梁降低最多，，其次是钢板压条锚固方式。CFRP板加固对抑制试验梁前期挠度增加作用不明显，对减小试验梁的后期挠度效果显著。梁端锚具很好的限制了CFRP板的滑移和延迟CFRP板的剥离，显著提高了加固梁的受弯性能。
[Abstract]:In recent years, with the rapid development of national economy and the rapid growth of traffic volume, while a large number of new highway and bridge construction, due to old disrepair, the original design standards are low, not to meet the current traffic volume and vehicle weight and other reasons. Many old bridges are becoming sick bridges and dangerous bridges, which seriously hinder the development of regional economy. Therefore, the cost of research and development is low. It is of great significance for the highway construction of our country to use and put into use the bridge structure strengthening technology with good technical effect. Strengthening bridge structure with CFRP slab is a reinforcement technique that has been studied in recent years. However, one of the key problems in the strengthening technology of CFRP plate is the efficiency of strengthening CFRP slab. In this paper, four test beams are designed, one of which is a contrast beam. Three reinforced beams with different anchoring methods for CFRP plate. Aiming at the problems of high production cost and difficult to be processed, CFRP plate is easily damaged and the anchoring force is low. In this paper, a hybrid anchoring device for composite colloidal bonding and steel plate clamping with perforated CFRP plates is designed. The relationship between the load value and the strain of concrete, the strain of steel bar, the deflection of test beam is analyzed, and the utilization efficiency of CFRP slab is also studied. The stiffness and ductility of the test beam are analyzed. Finally, the peeling theory of CFRP plate is analyzed. The results show that the cracking load of concrete beams strengthened with CFRP plates is slightly increased but not significant. However, the yield load and ultimate load of the test beam are increased by about 30%. The strength utilization ratio of CFRP slab can be improved by restraining the growth of the strain of steel bar and the strain of concrete compression zone. To limit the crack width and reduce the crack spacing, the embedded anchoring method of CFRP plate is the most effective. The ductility of all the strengthened beams is lower than that of the contrast beams to some extent, the reduction of the reinforced beams with U-type hoop Anchorage is the most. Secondly, the reinforcement of steel strip anchoring method, CFRP plate has no obvious effect on the pre-deflection increase of test beam. Anchorage at the end of the beam limits the slip of the CFRP plate and the delay-delamination of the CFRP plate, and improves the flexural behavior of the strengthened beam.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.72

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