Correlation of Acoustic Emissions and Pressure Stimulated Currents recorded in Alfas-stone specimens under three-point bending. The role of the specimens’ porosity: Preliminary results.

Abstract

The investigation of the mechanical status of materials subjected to load levels approaching these causing macroscopic fracture seriously concerns the structural engineering community. There are several experimental works demonstrating a series of sensing techniques capable of providing indications warning about the upcoming catastrophic failure of the material. In the present work, beam-shaped Alfas-stone specimens were subjected to three-point bending until fracture. During loading the Acoustic Emissions (AE) and the Pressure Stimulated Currents (PSC) generated were recorded. Correlation of acoustic and electric signals is attempted aiming to enlighten the fracturing mechanisms activated within the specimens. Special attention is paid to the very last instants before macroscopic fracture. Moreover, the role of the specimens’ porosity on the acoustic and electric activity is studied. The results show significant similarities of qualitative nature with corresponding experiments conducted on other building materials.