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首页> 外文学位 >Contribution a la caracterisation des betons endommages par des methodes de l'acoustique non lineaire. Application a la reaction alcalis-silice.
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Contribution a la caracterisation des betons endommages par des methodes de l'acoustique non lineaire. Application a la reaction alcalis-silice.

机译：非线性声学方法有助于表征受损混凝土。应用于碱-二氧化硅反应。

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The aim of this thesis is to contribute to the non-destructive characterization of concrete materials damaged by alkali-silica reaction (ASR). For this purpose, some nonlinear characterization techniques have been developed, as well as a nonlinear resonance test device. In order to optimize the sensitivity of the test device, the excitation module and signal processing have been improved. The nonlinear tests were conducted on seven samples of concrete damaged by ASR, three samples of concrete damaged by heat, three concrete samples damaged mechanically and three sound concrete samples. Since, nonlinear behaviour of the material is often attribute to its micro-defects hysteretic behaviour, it was shown at first that concrete damaged by ASR exhibits an hysteresis behaviour. To conduct this study, an acoustoelastic test was set, and then nonlinear resonance test device was used for characterizing sound concrete and concrete damaged by ASR. It was shown that the nonlinear technique can be used for characterizing the material without knowing its initial state, and also for detecting early damage in the reactive material. Studies were also carried out on the effect of moisture regarding the nonlinear parameters; they allowed understanding the low values of nonlinear parameters measured on concrete samples that were kept in high moisture conditions. In order to find a specific characteristic of damage caused by ASR, the viscosity of ASR gel was used. An approach, based on static creep analysis, performed on the material, while applying the nonlinear resonance technique. The spring-damping model of Maxwell was used for the interpretation of the results. Then, the creep time was analysed on samples damaged by ASR. It appears that the ASR gel increases the creep time. Finally, the limitations of the nonlinear resonance technique for in situ application have been explained and a new applicable nonlinear technique was initiated. This technique use an external source such as a mass for making non-linearity behaviour in the material, while an ultrasound wave is investigating the medium.;Keywords. Concrete, Alkali-silica reaction, Nonlinear acoustics, Nonlinearity, Hysteresis, Damage diagnostics.
机译：本文的目的是为碱-硅反应（ASR）损坏的混凝土材料的无损表征做出贡献。为此，已经开发了一些非线性表征技术以及非线性共振测试装置。为了优化测试设备的灵敏度，对激励模块和信号处理进行了改进。非线性测试是对ASR损坏的七个混凝土样品，热损坏的三个混凝土样品，机械损坏的三个混凝土样品和健全的混凝土样品进行了非线性测试。由于材料的非线性行为通常归因于其微缺陷的滞后行为，因此首先证明了被ASR损坏的混凝土表现出滞后行为。为了进行这项研究，设置了声弹性测试，然后使用非线性共振测试装置来表征良性混凝土和被ASR损坏的混凝土。结果表明，非线性技术可用于在不知道其初始状态的情况下表征材料，也可用于检测反应性材料的早期损坏。还研究了水分对非线性参数的影响。他们可以理解在高湿度条件下对混凝土样品测得的非线性参数的低值。为了找到由ASR引起的特定损伤特征，使用了ASR凝胶的粘度。在应用非线性共振技术的同时，对材料执行基于静态蠕变分析的方法。 Maxwell的弹簧阻尼模型用于解释结果。然后，分析了被ASR损坏的样品的蠕变时间。看来ASR凝胶会增加蠕变时间。最后，解释了非线性共振技术在现场应用中的局限性，并提出了一种新的可应用的非线性技术。该技术使用诸如质量之类的外部源在材料中进行非线性行为，而超声波正在研究介质。混凝土，碱硅石反应，非线性声学，非线性，滞后，损伤诊断。

著录项

  • 作者

    Kodjo, Apedovi.;

  • 作者单位

    Universite de Sherbrooke (Canada).;

  • 授予单位 Universite de Sherbrooke (Canada).;
  • 学科 Geophysics.;Engineering Civil.;Physics Acoustics.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 127 p.
  • 总页数 127
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 地球物理学;声学;建筑科学;
  • 关键词

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