拔出法现场检测水泥砂浆抗压强度试验方法标准研究

发布时间：2018-03-05 01:05

本文选题：先装拔出法　切入点：后装拔出法　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：在砌体结构加固工程中,采用配置有钢筋网片的水泥砂浆面层加固承重墙或砖柱是一种被广泛采用的方法,水泥砂浆面层的材料强度直接体现了其加固效果。目前行业中尚未提出专门针对水泥砂浆面层抗压强度现场检测的方法和技术手段,也缺乏相应的的技术规范和标准。本文通过对实际工程施工现场的加固墙体进行先装拔出法试验和后装拔出法试验,分析拔出法现场检测水泥砂浆面层抗压强度的可行性。现场试验的加固材料采用M10、M15、M20、M25、M30、M35、M40、M45、M50九个强度等级的水泥砂浆,共设置54个先装拔出法试验组和54个后装拔出法试验组。采用最小二乘法原理对得到的拔出力和对应的立方体抗压强度数据进行线性拟合,分别得出相应的先装拔出法回归公式和后装拔出法回归公式,并对回归公式进行模型整体检验、回归系数检验,对给定的拔出力条件下水泥砂浆实际强度个别值区间进行估计。同时,对拔出法现场试验时可能出现的破坏形态进行总结和分析。最后在相同的试验条件下,将水泥砂浆和三种纤维砂浆的回归曲线进行比较,将先装拔出法和后装拔出法检测水泥砂浆的回归曲线进行比较,以便对比分析各回归曲线之间的差异和关联性。本文对水泥砂浆拔出法现场检测的试验装置进行了技术改进和创新,试验研究在实际工程现场条件下进行,对现场检测条件下的先装拔出法和后装拔出法的测试操作流程进行了详细规定。本文试验采用的试验装置、试件制作工艺、测试环境、仪器操作方法、水泥砂浆加固层厚度、测点中心与钢筋网距离等条件和因素均已确定,能准确反映不同强度等级水泥砂浆面层的拔出力的变化规律,便于测强曲线的建立。拔出法是一种准确、便捷、经济的微破损性现场检测方法,本文研究内容对该现场检测方法的操作流程和试验内容进行了详细规定,推动了该方法的工程应用,其研究成果能为相关技术标准的制订提供了重要依据,并能取得广泛的社会效益。
[Abstract]:In the masonry structure strengthening project, it is a widely used method to reinforce the bearing wall or brick column with reinforced concrete mortar surface layer. The material strength of cement mortar surface layer directly reflects its reinforcement effect. At present, no specific methods and technical means have been put forward to detect the compressive strength of cement mortar surface layer in situ. There is also a lack of corresponding technical specifications and standards. In this paper, through the test of pre-pull-out method and post-pull-out test of the strengthened wall on the site of actual engineering construction, The feasibility of in-situ testing of compressive strength of cement mortar surface layer by pull-out method is analyzed. The cement mortar of nine strength grades M10M15 M20 M30 M30 M35 and M40M45 / M50 is used in the field test. A total of 54 pre-pull-out test groups and 54 post-pull-out test groups were set up. The pull-out force and the corresponding cube compressive strength data were fitted linearly by using the principle of least square method. The corresponding regression formulas of pre-pull-out method and post-pull-out method are obtained respectively, and the regression formula is tested by the whole model and the regression coefficient. The actual strength of cement mortar is estimated under the given pull-out force. At the same time, the failure patterns that may occur in the field test of pull-out method are summarized and analyzed. Finally, under the same test conditions, The regression curves of cement mortar and three kinds of fiber mortar are compared. In order to compare and analyze the difference and correlation among the regression curves, this paper has improved and innovated the test equipment of cement mortar pull-out method, and the experimental research has been carried out under the actual engineering site conditions. The test operation flow of pre-loading pull-out method and post-loading pull-out method under the condition of field testing is specified in detail. The test equipment, test technology, test environment, instrument operation method, thickness of cement mortar reinforcement layer are used in this paper. The conditions and factors such as the distance between the center of the measuring point and the steel mesh have been determined, which can accurately reflect the law of the pull-out force of cement mortar with different strength grades, and facilitate the establishment of the strength measurement curve. The pull-out method is accurate and convenient. In this paper, the operation flow and test contents of the field detection method are specified in detail, which promotes the engineering application of the method. The research results can provide an important basis for the formulation of relevant technical standards, and can achieve a wide range of social benefits.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ177.62

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