自然科学版 英文版
自然科学版 英文版
自然科学版 英文版

您目前所在的位置:首页 - 期刊简介 - 详细页面

中南大学学报(自然科学版)

Journal of Central South University

第48卷    第11期    总第279期    2017年11月

[PDF全文下载]    [Flash在线阅读]

    

文章编号:1672-7207(2017)11-3069-07
基于CT技术的混凝土孔隙结构冻融损伤试验
田威,韩女, 张鹏坤

(长安大学 建筑工程学院,陕西 西安,710061)

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。

 

关键字: 混凝土;冻融循环;CT技术;三维重建;盒维数

Experiments on the freeze-thaw damage of concrete porous structure based on CT technique
TIAN Wei, HAN Nü, ZHANG Pengkun

School of Civil Engineering, Chang’an University, Xi’an 710061, China

Abstract:The computed tomography (CT) technology was used to quantitatively scan the evolution of the concrete damage process under freeze-thaw cycles, and the batch of 2D slice images was obtained. Based on CT technology,the 3D porous structure of concrete was reconstructed by full digital image processing analysis. The spatial distribution characteristics and evolution law of 3D porous structure were obtained. The relationships between porosity and uniaxial compressive strength were analyzed. And the relationships between the porous structure and the freeze-thaw cycles were described quantitatively by the fractal theory. The results show that the pore distribution of concrete material has important effect on concrete mechanical property and macro damage characteristics. The volume porosity decreases with the increase of freeze-thaw cycles and there is a negative correlation between the uniaxial compressive strength and porosity. The fractal dimension of the pore structure presents “down—up” trend with the increase of the number of freeze-thaw cycles. The porous structure evolution is changed from chaos to order and then to a process of disorder.

 

Key words: concrete; freeze-thaw cycle; CT technique; 3D reconstruction; fractal dimension

中南大学学报(自然科学版)
  ISSN 1672-7207
CN 43-1426/N
ZDXZAC
中南大学学报(英文版)
  ISSN 2095-2899
CN 43-1516/TB
JCSTFT
版权所有:《中南大学学报(自然科学版、英文版)》编辑部
地 址:湖南省长沙市中南大学 邮编: 410083
电 话: 0731-88879765(中) 88836963(英) 传真: 0731-88877727
电子邮箱:zngdxb@csu.edu.cn 湘ICP备09001153号