ABSTRACT
The unit strain from the strain gauges situated on the top of CFRP is used to understand the failure mechanism of CFRP strengthened RC structures. It has been interpreted that the increase in the strain gauges results from CFRP being pulled due to cracking. Decrease in unit strain is regarded as damage in the bonding. However, the distance to the strain gauge, the crack orientation and crack type effects the unit strain behavior directly. Therefore, more detailed investigation is needed to clarify the fracture mechanism of CFRP strengthened RC structures. Therefore, based on moment tensor analysis of Acoustic Emission (AE) signals, AE-SiGMA method (Ohtsu 1991, Grosse 2008) is applied to clarify cracking mechanisms of CFRPstrengthened RC beams. By AE-SiGMA, crack kinematics of locations, types and orientations are quantitatively determined. The method is known to be successfully applied for identification of crack kinematics of RC specimens (Ohtsu 1998, Ohno 2010).
