Damage analysis of concrete structures by means of B-value technique

The paper deals with the non-destructive monitoring of civil engineering structures damage by the Acoustic Emission (AE) of the cracks that can occur inside the concrete material. The damage of the concrete material has been evaluated by analyzing AE signals during the compression tests. In order to prevent the loss or partial acquisition of signals a multi-triggering acquisition modality and adaptive evaluation of the Acquisition Time Interval (ATI) have been used. The analysis is based on the Gutenberg-Richter law (GBR), that is the relationship between the magnitude and total number of events of earthquakes in established region and time period. Through the GBR law the b-value was valued and used to select the critical AE signals that identify damage events. Experimental tests have allowed to highlight correspondence between the critical AE signals and the damage in the material.