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多孔水泥基材料中的水分运动对研究其劣化过程和耐久性非常重要.一些传统的测定水泥基材料中水分运动的方法大都基于材料的质量变化、电学或者核磁共振等特性.本文应用先进的实时热中子成像技术,通过理论分析和试验研究,对水泥基材料中的水分运动包括水分向内部渗透和向外部扩散进行了可视化再现和定量测定.由于热中子对氢原子强烈的衰减特性,热中子成像表现出对材料中水分存在的高度敏感性.基于点散射函数(PScF)建立了对原始成像所含中子传输信息的定量分析方法.对未开裂和开裂砂浆试件的水分渗透过程以及干燥失水过程进行了实时热中子成像试验.结果显示,热中子成像是可视化观测和定量测定多孔水泥基材料中水分运动特性的有力工具,试验结果将有助于更好地理解水泥基材料的劣化规律以寻求提高其耐久性的措施.
Moisture movement in porous cement-based materials is very important for the study of its degradation process and durability.Most of the traditional methods for determining water movement in cement-based materials are based on material quality changes, electrical or nuclear magnetic resonance, etc. This paper applies advanced real-time Thermal neutron imaging technology, through theoretical analysis and experimental study, the moisture movement in cement-based materials, including water infiltration and external diffusion to the visual reproduction and quantitative determination of the thermal neutron hydrogen atoms due to the strong attenuation characteristics, Thermal neutron imaging shows a high sensitivity to the presence of moisture in the material. A quantitative analysis method based on the point scattering function (PScF) is established for the neutron transport information contained in the original image. The moisture permeability of uncracked and cracked mortar specimens Process and dry dehydration process were performed in the real-time thermal neutron imaging experiments.The results show that thermal neutron imaging is a powerful tool for visual observation and quantitative determination of water movement characteristics in porous cement-based materials and the test results will help to better understand The deterioration of cement-based materials in order to seek ways to improve its durability.