【作者】 秦丽辉；

【导师】 王宗林；

【作者基本信息】 哈尔滨工业大学 ， 桥梁与隧道工程， 2014， 博士

【摘要】 近年来随着社会经济的发展，公路的交通负荷越来越重，现有桥梁频繁出现病害和损伤，承载力降低，使用性能下降。我国目前的桥梁工程建设已经从过去的大面积新建工程转为新建与已建桥梁补强加固相结合的阶段。据资料显示，加固工程相对新建工程而言，可节约大概40%左右的投资成本，缩短约50%时间成本，具有明显的经济优势。既有结构的承载力减弱，主要体现在抗弯和抗剪两个方面，且大部分的损伤体现在挠度、裂缝和表面破损等指标。近年来新兴的玄武岩纤维布不仅抗拉强度与弹性模量较高，而且其粘结性、耐热性和抗腐蚀性等物理性能优越，在土木结构和构件中得到广泛使用，尤其在钢筋混凝土结构加固补强方面的应用越来越受到青睐。本文在玄武岩纤维布加固损伤钢筋混凝土梁的试验基础上，研究梁的抗弯、抗剪性能及挠度裂缝计算方法，以期为玄武岩纤维布加固损伤钢筋混凝土梁的设计、施工提供理论依据。论文中先对玄武岩纤维布加固损伤混凝土梁抗弯性能开展研究，通过外贴玄武岩纤维布加固损伤钢筋混凝土梁的试验，研究不同配筋率、加固量、初始荷载及加载历史情况下梁的屈服荷载、破坏荷载及钢筋、混凝土和玄武岩纤维布的应力应变变化规律，研究给出不同破坏模型下玄武岩纤维布加固混凝土梁的抗弯承载力计算公式。又对玄武岩纤维布加固损伤混凝土梁的抗剪性能开展研究，研究不同剪跨比、加固量、初始荷载等情况下梁的抗剪承载力变化规律。修正了玄武岩纤维布加固损伤混凝土梁的抗剪承载力计算公式。同时文中还对玄武岩纤维布加固梁的挠度和裂缝计算开展研究。分析玄武岩纤维布加固损伤钢筋混凝土梁的挠度及裂缝变化规律，修正了玄武岩纤维布加固梁的挠度和裂缝间距及裂缝宽度计算方法。结合工程实际，通过对哈伊公路桥梁采用玄武岩纤维布加固研究，验证了本文提出的玄武岩纤维布加固损伤混凝土梁抗弯、抗剪承载力计算公式的有效性，可为实际加固工程提供参考。更多还原

【Abstract】 Due to the economic fast growing, highway traffic loads are increased and become more serious. Therefore, the bridges structures have been damaged frequently and the bearing capacity decreased with time. In China, the process of bridges construction is focused on the combination of new construction and strengthening methods to build new bridges or to strengthen old bridges. Comparing with new construction of bridges structure, the strengthening methods can save about40%of the investment costs and they can reduce the costs about50%. Thus it has evident economic benefits. The reduction of bearing capacity of bridge structure includes two main aspects of flexural and shear capacity. Moreover, most damages are denoted by deflection, cracks and failure mode etc. Basalt fiber reinforced plastics has a high tensile strength and modulus of elasticity. At the same time, it has higher physical performance, such as good adhesion, heat resistance, and corrosion resistance. Thus, basalt fiber reinforced plastics is ideal for civil engineering structures or construction components, and it is a perfect choice especially for seismic strengthening of concrete structures.According to the experimental works in the laboratory of Reinforced Concrete (RC) beam strengthened with Basalt Fiber Reinforced Plastics (BFRP), the calculation method of flexural capacity, shear capacity, deflection and crack were studied to provide theoretical essence for damaged of RC beam strengthened with BFRP sheet. In this thesis the flexural behavior of RC beam strengthened with BFRP sheet was studied. The important factors of the experiments programs include varying of beam reinforcement ratio, number of BFRP sheet layer; pre-load and loading step history were considered. Yield load, failure load and strain of steel, concrete’s strain, basalt fiber’s strain were predicted and analyzed. Then the shear capacity of RC beam strengthened with BFRP sheet was analyzed for different shear span ratio, number of BFRP sheet layer and pre-loading program within experimental works.At the same time, the deflection and cracks values of damaged RC beam strengthened with BFRP sheet with the increasing of the load were analyzed in this thesis. The changing rule of infection and cracks of damaged RC beam strengthened with BFRP sheet was analyzed. The calculation method of deflection and cracks were measured to beam’s stiffness improvement and cracks width reduction.This study was presented HAYI bridge that was strengthened with BFRP sheet to verify the validity of the presented calculation methods of flexural and shear capacity of damaged RC beam strengthened with BFRP sheet. These calculation formulas can be used to in the actual strengthening construction cases.更多还原