玄武岩纤维布加固损伤混凝土梁力学性能研究

发布时间：2018-07-03 14:11

本文选题：玄武岩纤维布 + 损伤混凝土梁　；参考：《哈尔滨工业大学》2014年博士论文

【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。
[Abstract]:In recent years, with the development of social economy, the traffic load of the highway becomes more and more heavy, the existing bridges frequently appear diseases and injuries, the bearing capacity is reduced, and the performance of the existing bridges is decreased. At present, the bridge construction in our country has changed from a large area of newly built projects to a stage of combining the new construction with the reinforcement of the existing bridges. According to the data, the reinforcement project can save about 40% of the investment cost and shorten about 50% of the time cost compared with the new project, which has obvious economic advantages. The bearing capacity of the existing structure is weakened, mainly in the aspects of bending and shear resistance, and most of the damage is reflected in the indexes of deflection, crack and surface damage. In recent years, new basalt fiber cloth not only has high tensile strength and elastic modulus, but also has excellent physical properties, such as adhesion, heat resistance and corrosion resistance, so it is widely used in civil structures and components. Especially the application of reinforced concrete structure reinforcement is more and more popular. On the basis of the experiment of strengthening damaged reinforced concrete beams with basalt fiber sheets, this paper studies the calculation methods of bending, shear properties and deflection cracks of the beams, in order to design the reinforced concrete beams strengthened with basalt fiber sheets. Construction provides theoretical basis. In this paper, the flexural behavior of damaged concrete beams strengthened with basalt fiber sheets is studied firstly, and the different reinforcement ratio and reinforcement amount are studied through the experiment of strengthening damaged reinforced concrete beams with outer basalt fiber sheets. Under the initial load and loading history, the yield load, the failure load and the stress-strain variation of steel bar, concrete and basalt fiber cloth, The formulas for calculating the flexural capacity of concrete beams strengthened with basalt fiber sheets under different failure models are presented. The shear resistance of damaged concrete beams strengthened with basalt fiber sheets is studied, and the shear bearing capacity of beams under different shear span ratio, reinforcement amount and initial load is studied. The formula for calculating the shear capacity of damaged concrete beams strengthened with basalt fiber sheets is modified. At the same time, the deflection and crack calculation of the beams strengthened by basalt fiber cloth are also studied. The deflection and crack variation of reinforced concrete beams strengthened with basalt fiber sheets are analyzed, and the calculation method of deflection, crack spacing and crack width of beams strengthened by basalt fiber sheets is modified. Combined with the engineering practice, the basalt fiber cloth is used to reinforce the Hay highway bridge, which verifies the validity of the calculation formula of the flexural and shear bearing capacity of the damaged concrete beam strengthened by the basalt fiber cloth in this paper. It can provide reference for practical reinforcement engineering.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU375.1

【参考文献】