基于CT技术的混凝土孔隙结构冻融损伤试验

发布时间：2018-06-28 20:50

本文选题：混凝土 + 冻融循环　；参考：《中南大学学报(自然科学版)》2017年11期

【摘要】：运用电子计算机断层扫描(CT)技术对经历冻融循环后的混凝土试样细观损伤过程进行实时扫描,获得二维断层扫描图像。在此基础上,运用图像处理技术对孔隙结构进行三维重建,得到不同冻融循环次数下试样内部孔隙结构的空间分布特征与演化规律,以此分析孔隙结构与单轴抗压强度之间的关系。运用分形理论对冻融环境下试样孔隙结构与冻融循环次数的关系进行定量化描述。研究结果表明:试样内部孔隙的结构分布特征和演化规律与其力学性质和宏观破损特征密切相关。在冻融循环作用下,混凝土孔隙率随冻融循环次数的增加而逐渐增大,并与单轴抗压强度呈负相关;混凝土试样孔隙盒维数呈现初期降低后期增加的变化规律,即在孔隙结构的扩展经历了复杂无序—单一有序—复杂无序的演化过程。
[Abstract]:The microcosmic damage process of concrete samples after freeze-thaw cycle was scanned by computer tomography (CT), and two-dimensional scanning images were obtained. On this basis, the three-dimensional reconstruction of pore structure is carried out by using image processing technology, and the spatial distribution characteristics and evolution law of pore structure in samples under different freeze-thaw cycles are obtained. The relationship between pore structure and uniaxial compressive strength is analyzed. The relationship between the pore structure and the number of freeze-thaw cycles in freeze-thaw environment was quantitatively described by fractal theory. The results show that the distribution and evolution of pore structure are closely related to its mechanical properties and macroscopic damage characteristics. Under the action of freeze-thaw cycle, the porosity of concrete increases with the increase of freeze-thaw cycle times, and is negatively correlated with uniaxial compressive strength. In other words, the expansion of pore structure has experienced the evolution process of complex disorder, single order and complex disorder.
【作者单位】：长安大学建筑工程学院;
【基金】：国家自然科学基金资助项目(51009010,51379015,51579013)~~
【分类号】：TU528

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