Destructuration of typical Sicilian calcarenites

The paper discusses some interesting features of Sicilian fine grain calcarenites. Uniaxial, triaxial, oedometer and isotropic compression tests were undertaken on intact specimens of two types of calcarenite in order to investigate their mechanical characteristics It was found that the strength and deformability is significantly influenced by the structure (fabric and bonding) and by the destructuration processes. A better understanding of fracture development behaviour is gained through a combination of acoustic emission and photographic monitoring on non-homogeneous samples with natural pre-existing heterogeneities due to cementation or to density. The results show that the destructuration and fracture propagation, as well as the structural strength, are highly dependent on the position and distribution of heterogeneities in the sample. With the Marsala calcarenite, the critical state was not reached, even with large strains, while with the Palermo calcarenite the critical state was reached for lower strain values and the material demonstrated the yielding behaviour typical of brittle rocks.