Wendy Desadeleer

Acoustic Emission (AE) and Nonlinear Elastic Wave Spectroscopy (NEWS) for online monitoring of concrete curing.

An integrated system of dynamic nondestructive experiments for material process monitoring is proposed, consisting of a combination of the AE technique with Nonlinear Elastic Wave Spectroscopy (NEWS). Using this system, we evaluate the microstructural properties of freshly poured concrete during hydration, with the ultimate goal to correlate these properties to its long-term behavior. The integrated system allows online monitoring of the condition parameters, of the internal microstructural activity by continuously triggering AE events and of the linear and nonlinear elastic properties of the microstructure through ultrasonic pulsed and continuous wave transmission measurements at regular time intervals. The internal temperature readings, the evolution in the acoustic emission events and the behavior of the linear and nonlinear elastic properties can be related to the different stages in the hydration process of concrete. The data are analyzed as a function of the degree of hydration for various concrete compositions during the first three days of the hydration process.