Context of the master thesis

Acoustic emission (AE) is a non-destructive testing technique used to monitor cracking in concrete [1]. It consists in recording at several locations of the concrete specimen waves that are generated by the release of energy when cracking occurs. If the wave velocity in the concrete is known, it is then possible to locate where the cracking event originates from.

The problem we wish to tackle in this master thesis is the use of acoustic emission for crack localization at early age in concrete, when the wave velocity changes rapidly due to the evolution of the micro-structure of concrete from a liquid to a solid state. This requires proper self-calibration of the acoustic emission system to track in real-time the wave velocity in the material and use it for an accurate crack localization.

References

[1] M. Ohtsu. Acoustic Emission and Related Non-destructive Evaluation Techniques in the Fracture Mechanics of Concrete: Fundamentals and Applications. Elsevier Science, 2015

[2] E. Tsangouri, G. Karaiskos, Arnaud Deraemaeker, D. Van Hemelrijck, and D. Aggelis. Assessment of acoustic emission location accuracy on damaged concrete. Construction & Building Materials, 129:163–171, December 2016

Objectives of the master thesis

The main objective is to implement a self-calibrating acoustic emission monitoring system to monitor cracking in early-age concrete. In addition to the traditional acoustic emission device, a piezoelectric transducer will be embedded inside the concrete specimen and excited with a pulse at regular time intervals. Knowing the position of this transducer, i.e. the source location, the signals recorded from the AE system will be used to calibrate the wave velocity. This in turn will be used to locate the acoustic events due to cracking.

Arnaud Deraemaeker

aderaema@ulb.ac.be)

Jérôme Carette  (jecarett@ulb.ac.be)

English/French

Civil Engineering

The student must have an interest in Structural Dynamics, Cementitious materials and Concrete behavior, basic programming skills in Matlab and an interest in experimental testing.