Mechanical and Fracture Characterisation of an Earthen Material for Eco-Friendly Structural Applications

In the present research work, the mechanical and fracture properties of a specific earthen material, named shot-earth 772, are experimentally investigated. The shot-earth mixture, consisting of 7 parts of excavated soil, 7 parts of aggregate and 2 parts of cement (by volume), is projected at high velocity onto a surface, by adding a little amount of water at the spraying nozzle. An experimental campaign, consisting of compressive and three-point bending tests on unnotched and edge-notched specimens, is performed in order to determine both the compressive and flexural strengths and the fracture toughness. In particular, cubic and prismatic specimens are extracted from a shot-earth sample (800 mm × 800 mm × 100 mm) so that the direction of the applied load is perpendicular to the spraying one. The compressive and flexural strengths are determined according to the UNI-EN standards, whereas the fracture toughness is computed by means of the Modified Two-Parameter Model (MTPM).