X-rays CT and Mesoscale FEM of the Shot-Earth Material

The present contribution deals with the mechanical characterization of "shot-earth" material. Akin to shotcrete technology, the shot-earth material is made by a mix of cement, stabilized soil, aggregates and water that is installed by high- speed projection rather than by mechanical compaction to obtain structural elements and architectural finishings. The task of the ongoing researches it to set up a procedure to highlight as the characteristics and percentage of the components influence the elastic and plastic behaviour of the composite. For the first time, X-rays micro computed tomography (micro-CT) is used to investigate the effective composition of material cubical samples. Moreover, several image processing techniques are devised to enhance the acquisitions' quality and to extract the data necessary for the creation of a finite element model. This last permits to investigate the relations between the material/physical characteristics and properties of cubical samples of shot-earth. In particular, a numerical homogenization procedure is applied to obtain the main elastic mechanical properties of the material. These are compared to the results of a mechanical experimental campaign (compressive tests) conducted on the same cubical samples.