Breakage and ultimate states for a carbonate sand

Abstract

This paper presents data from ring-shear and one-dimensional compression tests, which have been used to cause breakage under large shear strains and large compressive stresses respectively. A comparison of the behaviour of carbonate sand in monotonic shear and compression is reported, focusing on void collapse, grading properties and particle shape evolution. Trends in breakage behaviour under compression and under shear were similar; however, ultimate steady-state properties differed significantly. The higher effect of shear breakage was evident, in that the steady-state gradings for sheared material had higher fractal dimensions, indicating that the gradings were finer, and morphological changes in particle shape were more significant. Steady-state gradings tended to be multi-fractal in nature rather than mono-fractal, and showed that a unique monotonic steady-state grading does not exist. Two types of ring-shear device were compared, and the differences between the results highlighted a dependence of steady-state properties on test apparatus configuration.