From liquid to solid bonding in cohesive granular media
From liquid to solid bonding in cohesive granular media
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DOI：
10.1016/j.mechmat.2011.06.008
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发表时间：
2011-10-01
影响因子：
3.9
通讯作者：
Radjai, Farhang
中科院分区：
文献类型：
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作者：
Delenne, Jean-Yves;Soulie, Fabien;Radjai, Farhang
研究了颗粒填料在干燥过程中由液体结合到固体结合的转变过程。颗粒最初被液体盐水浸湿，填料的凝聚力由毛细力保证，但溶质的结晶将液体键转变为部分胶结键。这种转变是由实验证明，通过测量样品的抗压强度在规定的时间间隔。我们的实验数据揭示了三种情况：(1)在临界饱和程度下，不形成固体键，内聚力基本保持不变；(2)黏结发生在试样表面，黏结前缘向试样中心扩散，黏结强度呈非线性增加；(3)当胶结前沿到达样品中心时，所有的粘结都是部分胶结的，但由于胶结的加强，粘聚力迅速增加。我们引入了一个基于参数键内聚规律和键结晶参数的模型。该模型准确地预测了相变和微观与宏观内聚关系。(C) 2011 Elsevier Ltd.版权所有。
We study the transition of a granular packing from liquid to solid bonding in the course of drying. The particles are initially wetted by a liquid brine and the cohesion of the packing is ensured by capillary forces, but the crystallization of the solute transforms the liquid bonds into partially cemented bonds. This transition is evidenced experimentally by measuring the compressive strength of the samples at regular intervals of times. Our experimental data reveal three regimes: (1) Up to a critical degree of saturation, no solid bonds are formed and the cohesion remains practically constant; (2) The onset of cementation occurs at the surface and a front spreads towards the center of the sample with a nonlinear increase of the cohesion; (3) All bonds are partially cemented when the cementation front reaches the center of the sample, but the cohesion increases rapidly due to the strengthening of cemented bonds. We introduce a model based on a parametric cohesion law at the bonds and a bond crystallization parameter. This model predicts correctly the phase transition and the relation between microscopic and macroscopic cohesion. (C) 2011 Elsevier Ltd. All rights reserved.