【作者】 纪梓斌；

【导师】 熊光晶；

【作者基本信息】 汕头大学 ， 结构工程， 2003， 硕士

【摘要】 针对现今单一纤维复合材料(FRP)加固混凝土结构加固效率低的问题，以及已有混杂纤维复合材料(HFRP)探索性研究存在的缺点，本文首次提出HFRP的合理匹配及其在混凝土结构加固中的应用研究。 鉴于国内外均有人对HFRP的耐久性和刚度提出疑问，笔者以综合分析HFRP各组分性能为基础，借鉴HFFP在各行业成功运用的实例，讨论HFRP的耐久性和刚度问题，探讨HFRP加固混凝土研究的可行性。据此，决定以用进口碳纤维(CF)和国产高强玻璃纤维(SGF)混杂配制适于混凝土结构加固的HFRP作为第一阶段研究任务。 在此基础上，以加固柱的延性、承载力、加固价格和CF性能发挥效率为指标，设计并进行了HFRP、碳纤维复合材料(CFRP)和高强玻璃纤维复合材料(SGFRP)加固柱的探索性对比实验研究，结果表明HFRP充分发挥了两种纤维各自的性能优势，克服了单一FRP的缺点。在提高相同承载力和刚度的前提下，既能显著提高被加固柱的延性，又能大幅度降低加固成本。 针对FRP试件的尺寸效应影响显著特点，以小试件进行对比实验研究基础上，提出一种新的实用FRP大试件拉伸实验方法。提出了几种HFRP配合比进行较为详细的拉伸对比试验研究，探讨破坏特征、工作机理，结果表明CF体积数V_C=0.198和0.247的HFRP较单一CFRP与其它配比的HFRP强度高，延性好，且价格低，仅刚度略低，匹配相对合理。 注意到当前混凝土梁板加固中FRP与混凝土之间胶缝粘结破坏是加固失效的主要模式之一。对粘结机理和既有加固施工方法进行了分析，指出粘结失效的主要原因是施工中未提供粘结加压(保证粘结强度三要素之一)所致。针对工程实际提出了简便易行的水垫加压施工工艺。开展小试块粘结加压实验研究，结果表明只要施加0.2kg/cm~2左右的接触压就能避免发生纤维与混凝土之间的脱胶破坏，大幅提高加固效率。 在以上研究基础上，将HFRP的合理匹配、水垫加接触压施工方法，用于一项屋面梁抗弯加固工程实践。加固设计发现我国在编标准中FRP设计强度取值法不合理，提出FRP强度设计值参照现行《混凝土结构设计规范》中钢筋强度设计值f_s取法更为合理，并实施了可靠的设计与施工方法。汕头大学硕士学位论文摘要 最后提出了今后HFRP加固混凝土结构的研究设想，主要是:HFRP的耐久性除进行合理的应用实例和理论分析外，还需通过试验研究进一步论证其可行性。应将合理匹配用于梁柱加固试件(作者已制作30个直径/高为1:3的HFRP加固柱试件和15根混凝土梁试件供后续实验研究之用。)，检验实际效果，并进行修正。应该在合理匹配研究的基础上，进行HFRP优化匹配研究。更多还原

【Abstract】 In order to improve the efficiency of strengthening concrete structure with sole fiber reinforced plastic (FRP) and overcome the disadvantages of the primary research of hybrid fiber reinforced plastic (HFRP), a new idea that strengthening concrete structure with reasonable matching of HFRP was proposed in this thesis firstly.In response to some researcher’s doubt on the durability and stiffness of HFRP in the world, the durability, stiffness of HFRP and its feasibility to strengthen concrete structure were discussed, based on the summary of properties of HFRP as well as its successful applications in several related fields. In the light of this, we decide to use imported carbon fiber (CF) and local high-strength glass fiber (SGF) to manufacture the HFRP which is adapted to concrete structure strengthening.Based on the discussion above, a primary comparative experiment of concrete columns externally wrapped with HFRP, carbon fiber reinforced polymer (CFRP) and high-strength glass fiber reinforced polymer (SGFRP) was carried out to study the ductility, load carrying capacity, strengthening cost of strengthened columns and the exerting efficiency of CF. Test results showed that the HFRP can fully exploit the advantages and overcome shortages of the materials. To improve the same load carrying capacity and stiffness of the specimens, HFRP can enable the strengthened columns certain ductility and a significant decrease of strengthening cost.Considering the size effect has a noticeable influence on the mechanism of FRPspecimen, after the comparatively experimental study of the small specimens, apractical and proper testing method of tensile properties of FRP to use big specimen was proposed. And a comparative experiment of HFRP with different matching wascarried out to study their failure feature and mechanism. The test results prove that, besides lower cost, the strength and the elongation ratio of HFRP in matching of volume ratios of CF Vc =0.198 and 0.247 are much higher than those of other matching of HFRP and sole CFRP, with a slight influence on stiffness. These two matching ratios are suitable and reasonable for the HFRP.Moreover, we notice that failure of the bonding interface between FRP and concrete is one of the main failure modes. After analyzing the bond mechanism and the strengthening arts, we pointed out that pressure is one of the three factors that ensure the bond strength, and the failure is mainly because of no pressure to the bonding interface. Then a convenient and practical construction technique of hydraulic pad-exerting-pressure was proposed. Through the small specimen tests, we found the failure of the bonding interface between FRP and concrete can be avoided and the efficiency can be highly improved, as long as the pressure is almost 0.2 kg/cm2.According to the results of the above experimental research, the reasonable matching of HFRP and construction technique of hydraulic pad-exerting-pressure were applied to a bending strengthening project of roofing frame beams. In the course of strengthening design, the shortcoming to determine the design strength value of FRP suggested by "Technical Specification for Strengthening Concrete Structure with Carbon Fiber Reinforced Polymer" was pointed out. A method consistent with the one to determine the design strength value of steel fs in "Code for Design of Concrete Structures" was proposed. And reliable design and construction method were employed in the strengthening project.At last some further research proposals of strengthening concrete structures with HFRP were presented: besides the theoretical descriptions of the durability of HFRP and its successful applications, further experimental research should be carried out to study its feasibility in strengthening concrete; in order to inspect and amend the practical effect of the reasonable matching, experimental study of concrete columns and beams (the author have fabricated 30 HFRP strengthening concrete columns with a diameter to height ratio of 1:3 and 15 concret更多还原