Characterizing the 3D Pore Structure of Hardened Cement Paste with Synchrotron Microtomography
Characterizing the 3D Pore Structure of Hardened Cement Paste with Synchrotron Microtomography
复制标题
DOI：
10.3151/jact.6.273
复制
发表时间：
2008-06
影响因子：
2
通讯作者：
M. Promentilla;T. Sugiyama;T. Hitomi;Nobufumi Takeda
中科院分区：
文献类型：
--
作者：
M. Promentilla;T. Sugiyama;T. Hitomi;Nobufumi Takeda
除了孔隙率之外，孔连通性和弯曲度的程度是水泥基材料的重要孔结构特征，以更好地理解微观结构对影响这些材料耐久性的运输过程的影响。同步加速器X射线计算机显微断层扫描是用来提供有关的三维（3D）孔隙结构的亚微米分辨率（0.5 μm/体素），使用的SPring-8设施在日本兵库县。本文提出了一种方法来表征硬化水泥浆体的孔隙空间取自不同的标本的各种年龄（2，7，和28天）的固化。通过定义孔隙阈值的基础上的过渡点的孔隙度-阈值依赖性曲线，孔隙从显微断层图像中的固体基质区分。此外，进行孔簇多重标记以获得关于孔连通性和相关有效孔隙度的信息。然后在最大扩散孔簇中进行3D随机游走模拟以评估扩散曲折度。本研究的结果表明，随着X射线成像系统可分辨的孔隙减少并变得更加不连续，扩散迂曲度增加。对孔隙阈值进行敏感性分析，以评价该方法的稳健性。
Aside from porosity, the degree of pore connectivity and tortuosity are important pore structure characteristics of cement-based materials to understand better the effect of microstructure on transport processes that influence the durability of these materials. Synchrotron X-ray computed microtomography is employed to provide information about the three-dimensional (3D) pore structure at submicron resolution (0.5 μm/voxel) using the SPring-8 facility in Hyogo, Japan. This paper presents a method to characterize the pore space of hardened cement pastes taken from different specimens of various ages (2, 7, and 28 days) of curing. By defining the pore threshold value on the basis of the transition point in the porosity-threshold dependency curve, the pores were distinguished from the solid matrix in the microtomographic images. Further, pore cluster multiple labeling was performed to gain information on the pore connectivity and the associated effective porosity. 3D random walk simulation in the largest percolating pore cluster was then conducted to evaluate the diffusion tortuosity. The results from this study provide indications of increasing diffusion tortuosity as pores that can be resolved by the X-ray imaging system decreased and became more disconnected. Sensitivity analysis to pore threshold value was performed to evaluate the robustness of the method.