Relative moment tensor inversion applied to concrete fracture tests

An advanced acoustic emission (AE) technique requires the recording of the AE activity and its whole waveforms during the loading of a specimen. Together with the calculation of the AE source coordinates, this enables numerous analysis techniques in the time and frequency domain including waveform comparisons and fault-plane solutions. The radiation pattern of AE sources and the seismic moment (as an equivalent for the emitted energy) as well as the type and orientation of the cracks can be determined using moment tensor inversion methods. This leads to a better understanding of the fracture process in the matrix and the debonding of the reinforcement. The methods have been applied to pullout tests to study the steel-concrete interaction in reinforced concrete cubes as well as in steel-fiber-reinforced concrete.