Micromechanically inspired investigation of cemented granular materials: part II- from experiments to modelling and back

This paper presents an experimental and analytical/numerical study of the mechanics of cemented granular materials (CGMs). This study incorporates both in situ X-ray tomography and regularised finite element simulations, whose combination offers a unique, complementary insight into the multiscale processes that drive the mechanical response of CGMs. Being the second in a set of a two-part contribution, this paper takes advantage of the image analysis tools developed in Part I to quantitatively explore the effects of boundary conditions on grain-scale processes as well as material properties. We reveal, for example, the influence of the degree of cementation on the spatial distribution of damage and suggest the existence of a local ultimate cement size distribution that is independent from the initial cement content. This paper also validates the predictions of a micromechanically inspired constitutive model at three different scales: in terms of the macroscopic response, the mesoscopic emergence of localisation patterns and the evolution of microscale inelastic processes. A unique feature that sets our model apart from previous CGM models is the adoption of only measurable internal variables, capable of representing grain-scale processes such as the damage of cement bridges. Its statistically representative experimental quantification is found to be in good agreement with the model predictions.

Automated summary

This paper presents an experimental and analytical/numerical study of the mechanics of cemented granular materials. The study combines in situ X-ray tomography and finite element simulations to gain insight into the multiscale processes that drive the mechanical response of these materials. The paper explores the effects of boundary conditions on grain-scale processes and material properties, and validates a micromechanically inspired constitutive model at different scales.