Experimental study on the cementation level in an artificial rock with crushable grains

The results of an experimental investigation of the effects of the degree of cementation on the mechanical behaviour of a porous artificial rock with crushable grains are presented. The studied material is an analogue of real cemented granular materials, such as pyroclastic weak rocks, carbonate sands, calcarenites and compacted decomposed granite. The present study aims to clarify the role of the degree of cementation in the relative importance or the sequential nature of mechanisms in natural material, i.e., granular rearrangement and breakage are expected to appear after de-bonding of particles. Cemented samples with different cement content were investigated. To understand the influence of the cementation, uncemented samples were reconstituted from a mixture of crushable grains and cement (not hydrated) in the same percentage by weight as the cemented (hydrated) samples, in order to obtain the same fraction of fines. Preliminary results show that, for the same confining stress, the cemented sample are more compressible than uncemented ones during isotropic compression; while, during axial loading, the cemented samples show a more rigid behaviour and a lower resistance.