基于气体渗透率和微裂纹特征分析的混凝土宏细观损伤规律研究

项目名称： 基于气体渗透率和微裂纹特征分析的混凝土宏细观损伤规律研究

项目编号： No.11502100

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 李萍

作者单位： 交通运输部公路科学研究所

项目金额： 25万元

中文摘要： 混凝土细观层次的微裂纹变化，在宏观层次上表现为材料损伤和渗透率增大。拟研究混凝土宏细观损伤变量之间的联系，建立基于气体渗透率评价混凝土损伤的方法。本研究首先制作不同损伤程度的混凝土试样，借助CT及近景摄影技术采集损伤试样表观及内部图像，经分析处理，获得表观裂纹矢量，并构建损伤混凝土的3D细观模型；采用数字图像处理手段分析微裂纹的空间特征分布，建立表观裂纹、三维裂纹特征与气体渗透率之间的关系；建立基于细观模型的有限元计算评估试样气体渗透的方法。其次，设计基于三轴仪的混凝土应力-应变-气体渗透率同步测量系统，建立基于气体渗透率的损伤本构模型。研究成果将对于定量评估混凝土损伤状态具有重要的应用价值。

中文关键词： 混凝土损伤；气体渗透率；微裂纹；损伤演化；损伤本构模型

英文摘要： The change of concrete micro-cracks shows material damage and permeability increase on the macro-level. The relations among the concrete damage variables on macro- and micro-level will be studied to establish the evaluation methods of concrete damage based on gas permeability. Firstly, different damage degrees of the concrete specimens will be produced, CT (Computed Tomography) and close-range photogrammetry technology will be used to take the images inner and apparent of the damaged specimens. Through image analysis processing, the vector of apparent crack will be got, and the 3D microscopic model of damage concrete samples will be built. The spatial distribution of concrete micro-cracks will be analyzed by means of digital image processing to build the relationship among apparent cracks, 3D-crack characteristic parameters and gas permeability; and the finite element method will be established to calculate gas permeability of specimens according to 3D microscopic model. Secondly, the simultaneous measurement system of stress - strain - gas permeability has been designed on basis of concrete geotechnical triaxial apparatus, and that will be used to establish the damage constitutive model based on gas permeability. The research results will have important application value for the quantitative damage assessment of concrete component.

英文关键词： Damage of Concrete ;Gas Permeability ;Micro-crack ;Damage evolution;Damage Constitutive