Statistical study of the crushing of limestone grains under shearing

摘要

The behavior of granular materials subjected to shear loading is often very complex to be correctly characterized. Loads on a discrete medium composed by several grains lead to a diffusion of stresses in the medium by contact and frictions between individual grains. This stress diffusion combined to inter-granular relative movements induces some cracking in the contact zones and even some complete grain crushing. This results in producing other grains of smaller size, changing thus the grain size distribution of the original material and its mechanical behavior law. Quantifying the rate of crushing is of significant importance for understanding the behavior of the granular medium. In the present work, a statistical study of crushing grains in a granular medium subjected to shear load is presented. A probabilistic model using the Weibull distribution is proposed to evaluate the rate of crushed grains as a function of the applied load. The material used in this study are limestone graine of diferent size, produced from crushing of healthy rock. The obtained results showed that the breakage of grains under shear load depends mainly on their dimensions and on the intensity of the applied load. Also, statistical modeling using the Weibull method produced satisfactory adjustment of the experimental data.