Prediction of compressive strength of concrete at a certain age requires an understanding of the hydration process and a means of moni- toring it. In the research presented in this paper an acousto-ultrasonic (AU) method was studied for monitoring strength development of con- crete. Changes in the waveform of the ultrasonic signal transmitted through the concrete during the first days of hydration were recorded and different stress wave factors extracted from the signal were analysed. The amplitude of the signal and the energy contained in the wave- form transmitted showed an almost linear correlation with compressive strength development.
University of Zagreb