Signal-Based Acoustic Emission Monitoring on Mortar Using Cement-Based Piezoelectric Sensors

Signal-based acoustic emission (AE) monitoring on mortar was performed under three types of static loading patterns: cubic-splitting, direct-shear, and pullout. Each of the applied loading patterns was expected to produce a distinguished fracture process on mortar. This study was the first to combine a cement-based piezoelectric sensor (such as an AE transducer) and a home-programmed DEcLIN monitoring system for monitoring the concrete fracture process in mortar It was found that the cement-based piezoelectric sensor has much better sensitivity and a much broader frequency domain response range as compared to traditional piezoelectric ceramic transducers after embedding into mortar specimens. The three-dimensional (3-D) localization of AE sources and the signal-based AE energy index obtained by the DEcLIN system were used to vividly explain and quantitatively evaluate the fracture processes of mortar specimens under various types of loadings. It was revealed that the fracture processes in mortar under the cubic-splitting and direct-shear loading patterns were evidently more brittle than that of the pullout test