Observations on microstructure of pumice particles using computed tomography
Observations on microstructure of pumice particles using computed tomography
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DOI：
10.1139/cgj-2012-0365
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发表时间：
2013-11-01
影响因子：
3.6
通讯作者：
Pender, Michael J.
中科院分区：
文献类型：
--
作者：
Kikkawa, Naotaka;Orense, Rolando P.;Pender, Michael J.
浮石在新西兰广泛分布，在基础设施建设中很重要，但不易在原位表征。它是一种独特的材料，它的颗粒在手指的压力下很容易被压碎，这使得它可以说是在世界各地发现的可碎土壤中最脆弱的一种。在这项研究中，我们使用x射线计算机断层扫描（CT）机扫描不同大小的浮石颗粒，以研究颗粒的微观结构。通过图像分析，我们能够比标准方法更准确地确定浮石的固体密度，标准方法显示密度随着粒径的减小而增加。CT扫描结果显示固体密度约为2.2 g/cm(3)，这与使用标准方法获得的最高值相似。另一方面，CT扫描的表观密度为0.89g/cm(3)，低于水的密度，因此证实浮石颗粒几乎都浮在水面上。此外，观察到表面空隙的体积远大于内部空隙的体积。此外，还对浮石砂的颗粒形态进行了分析，并与其他天然砂进行了比较。最后，分析表明浮石颗粒非常脆弱，不仅因为它们是多孔的，还因为它们的角度性质。
Pumice occurs widely in New Zealand and is important in infrastructure construction, but is not readily characterized in situ. It is a unique material, the particles of which crush easily under finger pressure, making it arguably the most delicate of the suite of crushable soils found in various locations around the world. In this study, we scanned pumice particles of different sizes using an X-ray computed tomography (CT) scanning machine to investigate particle microstructure. Using image analyses, we were able to determine the solid density of pumice more accurately than the standard method, which showed increasing density as particle size decreased. Results from the CT scanning showed a solid density of about 2.2 g/cm(3), which is similar to the highest value obtained using the standard method. On the other hand, the apparent density from CT scanning was 0.89g/cm(3), which is lower than the density of water, therefore confirming that almost all pumice particles float on water. In addition, the volume of surface voids was observed to be much greater than that of internal voids. Moreover, the particle shape of pumice sand was analyzed and compared to other natural sands. Finally, analyses showed that pumice particles are very fragile not only because they are porous, but also because of their angular nature.