The objective of this paper is to study the expanded clay material behaviour considering the crushability of its single grains. The probed material is characterized by a high internal porosity; randomly distributed inside its grains. The assembly behaviour was investigated considering the oedometric path and the fragmentation amount was quantified using the relative breakage coefficient (Br). Oedometric compression tests were performed on different loose samples with similar grain size distribution. In this paper, single grain indirect tensile tests were made to identify the microscopic parameters affecting the breakage occurring. The density effect was studied using a statistical approach and the calibration was made based on the indirect tensile tests results performed on individual grains. Authors further developed a crushing algorithm based on the experimental tests results performed on several dimensions ranges of single grains. The algorithm was implemented in the PFC3D software aiming to model the material’s macroscopic behaviour using discrete elements modelling (DEM). The analysis of the macroscopic response of a loose grain’s assembly was conducted using both the stress–displacement responses and the breakage factor. The comparison between experimental and numerical simulations shows the DEM’s potential, coupled with the fragmentation algorithm of the individual grains issued from the experimental single grains study, to reproduce the assembly’s mechanical behaviour. However, basing on the breakage factor Br, the DEM simulations performed herein are not in a good agreement with experimental ones; which will be discussed in this work.

中文翻译：

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膨胀黏土的等渗压缩行为，包括单个颗粒的可压碎性

本文的目的是考虑单颗粒的可压碎性，研究膨胀粘土材料的性能。被探查材料的特点是内部孔隙率高。随机分布在其谷物内部。考虑了测听路径，研究了组装行为，并使用相对破损系数（Br）量化了碎裂量。对具有相似粒度分布的不同松散样品进行测压测试。在本文中，进行了单晶间接拉伸试验，以确定影响断裂发生的微观参数。使用统计方法研究密度效应，并基于对单个晶粒进行的间接拉伸测试结果进行校准。作者根据在单个晶粒的多个尺寸范围上进行的实验测试结果，进一步开发了一种破碎算法。该算法是在PFC3D软件中实现的，旨在使用离散元素建模（DEM）对材料的宏观行为进行建模。使用应力-位移响应和破损因子对松散晶粒组件的宏观响应进行了分析。实验与数值模拟之间的比较显示了DEM的潜力，再加上从实验单颗粒研究中得出的单个颗粒的碎裂算法，可以再现组件的机械性能。但是，基于破损因子Br，此处执行的DEM模拟与实验模拟并不完全一致。