预应力孔道灌浆质量无损检测与快速评价技术研究

发布时间：2018-05-22 17:16

本文选题：预应力 + 孔道灌浆　；参考：《重庆交通大学》2014年硕士论文

【摘要】：近年来，随着预应力混凝土结构在工程中的普遍应用，对这类工程结构质量的检测也越来越受到重视。有粘结的后张拉预应力孔道灌浆是为了使预应力筋束与混凝土结合良好，将预应力分散分布于构件上，减轻锚具及结构两端负担；避免预应力筋束被锈化腐蚀而影响结构或构件的安全使用寿命及其耐久性。但是由于施工过程中工人灌浆技术的不成熟、孔道堵塞、水泥浆的膨胀率和稠度指标控制不好、压浆时压力不够或封堵不严、灌浆浆体的泌水率和流动度等性能指标未达到设计要求等原因，预应力孔道内部可能存在裂缝、空隙等，这些缺陷将会导致预应力筋局部得不到保护而锈蚀，影响预应力筋的寿命。预应力构件达不到设计要求，结构承载力下降，从而导致结构破坏。目前，我国尚无一套较成熟的测试技术标准，可用于预应力管道的灌浆质量评价。本文针对预应力预留管道内部灌浆质量的无损检测技术开展了较深入的理论和试验研究，利用应力波在混凝土中传播的各种参数变化的特点，采用已有无损检测经验及分析方法进行试验及数据分析处理等研究,本论文进行了以下工作： 1、阐述了无损检测技术的发展及其在预应力管道灌浆质量检测中的应用和特点。综合国内外发展现状，总结已有的检测方法及其存在的问题，重点探讨以弹性波属性为基础的无损检测技术的理论方法及其应用。 2、以弹性波属性的基本理论为依据，，通过对弹性波波速、频率和能量衰减属性的综合分析研究，建立各属性与孔道缺陷之间的相对应关系，形成了具有一定实验研究基础的测试理论。 3、基于以往冲击回波无损检测技术的方法与原理，提出了一套较完整的基于弹性波的无损检测检测评价体系,来对预留孔道内部灌浆的质量进行定性与定位分析。该评价体系综合了弹性波在介质中的传播速度、频率及能量衰减属性，权衡了各属性对缺陷的响应特性，利用这三种属性综合评价孔道灌浆质量减小了各单一属性评价指数影响因素的影响，达到了较理想的检测效果。 4、将本文的研究成果应用于现场工程预应力桥梁的管道压浆质量检测评估,结合现场实际检测的特点编制了相应的灌浆质量检测程序,建立诊断试验结论的模型,取得了良好的效果。证明了该套无损检测方法在实际检测过程中具有良好的工程适应性及可靠性,为同类工程的有效检测提供了有益的参考。
[Abstract]:In recent years, with the widespread application of prestressed concrete structures in engineering, more and more attention has been paid to the quality detection of these structures. The post-tensioned pre-stressed channel grouting is designed to combine the prestressed tendons with the concrete, distribute the prestress on the members, and reduce the burden on the anchors and the two ends of the structure. To avoid the corrosion of prestressing tendons to affect the safety service life and durability of structures or members. However, due to the immature grouting technology of workers, the blockage of holes, the poor control of the expansion rate and consistency index of the cement slurry, the insufficient pressure or the lax sealing during the grouting process, The performance indexes of grouting slurry, such as bleeding rate and fluidity, do not meet the design requirements, and there may be cracks and voids in the prestressing channels. These defects will lead to the failure of local protection and corrosion of prestressed tendons. The life of prestressed tendons is affected. The prestressed members can not meet the design requirements and the bearing capacity of the structure decreases, which leads to the destruction of the structure. At present, there is not a set of mature technical standard for grouting quality evaluation of prestressed pipeline in China. In this paper, a deep theoretical and experimental study has been carried out on the nondestructive testing technology of the internal grouting quality of the pre-stressed reserved pipeline, and the characteristics of the variation of various parameters propagating in concrete by the stress wave are used. In this paper, the following work has been done: (1) using the existing experience of nondestructive testing and analysis methods to carry out experiments and data analysis and processing, the following work has been done in this paper: 1. The development of nondestructive testing technology and its application and characteristics in the quality testing of prestressed pipeline grouting are described. In this paper, the existing testing methods and their existing problems are summarized, and the theoretical methods and applications of nondestructive testing technology based on elastic wave properties are discussed. 2. On the basis of the basic theory of elastic wave properties, through the comprehensive analysis and study of the elastic wave velocity, frequency and energy attenuation properties, the corresponding relationship between each attribute and the hole defect is established. The test theory with certain experimental research foundation has been formed. 3. Based on the previous methods and principles of impact echo nondestructive testing (NDT), a complete evaluation system based on elastic wave is proposed to qualitatively and localize the quality of internal grouting in reserved channels. The evaluation system synthesizes the properties of the velocity, frequency and energy attenuation of elastic wave in the medium, and balances the response characteristics of each attribute to the defect. The comprehensive evaluation of grouting quality by these three attributes reduces the influence of each single attribute evaluation index and achieves an ideal testing effect. 4. The research results of this paper are applied to the pipeline grouting quality detection and evaluation of the prestressed bridge in the field engineering, and the corresponding grouting quality detection program is compiled according to the characteristics of the field actual inspection, and the model of the diagnostic test conclusion is established. Good results have been achieved. It is proved that this nondestructive testing method has good engineering adaptability and reliability in the process of practical testing and provides a useful reference for the effective detection of similar projects.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4

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