河南地区回弹法检测混凝土强度测强曲线试验研究

发布时间：2018-03-31 19:26

本文选题：回弹法　切入点：影响因素　出处：《郑州大学》2017年硕士论文

【摘要】：混凝土结构在当前建设工程中占据着主导地位,但是混凝土质量问题时有发生,对混凝土质量的控制在实际工程中变得尤为重要。其中混凝土强度作为混凝土质量控制考核的关键因素之一,无论是新建建筑的验收还是既有建筑的评定与改造,都涉及到混凝土结构强度的评定问题。回弹法作为非破损检测技术中的基本方法之一,在现场检测过程中得到广泛的使用。目前河南地区回弹法使用的测强曲线是现行国家规程中的统一测强曲线,然而随着矿物掺合料的使用及混凝土结构向高强度方向的发展,使用统一测强曲线进行混凝土强度推定在河南地区实际应用过程中出现一定局限性。本课题从工程实际需要出发,严格按照现行国家规程中对制定地区测强曲线的要求,根据本地区混凝土实际生产工艺水平进行了回弹法测强曲线的试验研究,主要研究内容及成果如下:1、本课题在总结国内外对回弹法检测混凝土强度影响分析的基础上,主要从回弹仪、试验方法、混凝土材料几个方面对影响回弹法测强曲线的因素进行分析,通过整理分析各因素对回弹值以及混凝土强度的影响关系,确定本地区回弹法测强的试验方案。2、选用河南地区工程中常用的混凝土材料、养护条件及成型工艺进行混凝土试块的制作,使用Q值回弹仪进行回弹试验,并对试验数据进行处理分析,根据最小二乘法的原理采用多个函数模型进行回归拟合,然后进行回归方程式的精度和误差对比,得出适用于混凝土强度在10~70MPa的河南地区测强曲线。3、对得出的地区测强曲线进行适用性试验研究,并与国家现行规程中统一曲线进行误差对比,结果表明国家规程提供的统一曲线在本地区使用误差相对较大,地区测强曲线在推定精度方面明显提高,更符合本地区使用回弹法进行混凝土强度推定的实际应用情况。本课题通过进行试验研究,得出适用于河南地区回弹法检测混凝土抗压强度的地区测强曲线,该曲线有效测强范围10MPa~70MPa,相较于现行国家规程中的统一曲线回弹法测强范围有所提高,推定精度上也有明显的提高,可为制定符合本省回弹法测强曲线提供重要依据,同时为提高河南省非破损检测技术水平提供参考。
[Abstract]:The concrete structure occupies the leading position in the current construction project, but the concrete quality problem occurs from time to time, the control of the concrete quality becomes more and more important in the actual project.The concrete strength is one of the key factors in the quality control of concrete. Whether it is the acceptance of the new building or the evaluation and transformation of the existing building, it involves the evaluation of the strength of the concrete structure.As one of the basic methods of nondestructive detection, springback is widely used in the field detection process.At present, the strength measurement curve used by springback method in Henan area is the unified strength measurement curve in the current national code. However, with the use of mineral admixtures and the development of concrete structure to high strength direction,There are some limitations in the practical application process of concrete strength estimation by using unified strength measurement curve in Henan area.According to the actual engineering needs and in strict accordance with the requirements of the current national regulations for the establishment of the regional strength curve, the paper carries out an experimental study on the rebound strength curve according to the actual production technology level of the concrete in this area.The main research contents and results are as follows: 1. On the basis of summing up the analysis of the impact of rebound method on the strength of concrete at home and abroad, this subject mainly starts from the springback instrument and test method.Several aspects of concrete material analysis of the impact of springback method on the strength of the curve, through finishing analysis of the various factors on the springback value and the strength of concrete relations,To determine the test plan of the rebound method for strength measurement in this area, the concrete materials commonly used in Henan area engineering, the curing conditions and the forming process are selected to make the concrete test blocks, and the springback test is carried out by using the Q value springback instrument.The experimental data are processed and analyzed. According to the principle of least square method, multiple function models are used for regression fitting, and then the accuracy and error of regression equation are compared.The results show that the strength curve. 3 is suitable for the concrete strength measurement in Henan area of 10~70MPa. The applicability of the obtained curve is studied, and the error of the curve is compared with that of the unified curve in the current national regulations.The results show that the unified curve provided by the national code has a relatively large error in use in this area, and the prediction accuracy of the regional strength measurement curve is obviously improved, which is more in line with the actual application of the rebound method in the estimation of concrete strength in this area.The effective measuring range of the curve is 10MPa / 70MPa, which is higher than that of the unified curve rebound method in the current national regulations, and the presumption accuracy is also obviously improved, which can provide an important basis for the establishment of the strength measurement curve in accordance with the provincial springback method.At the same time, it provides a reference for improving the technical level of non-damage detection in Henan Province.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU755.7

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