The determination of the setting time (ST) of Roller Compacted Concrete allows to ensure the interface bonds quality in the case of multi-layered structures. In the first place, modeling the concrete solidification enhances the importance of the percolation phenomenon in the propagation of the ultrasonic waves. As a second stage, we use the propagation of the ultrasonic wave through an RCC sample and we consider the concrete as a spectral and energetic evolutive filter to determine and control the concrete setting in real time. Mechanical testings and SEM observations make it possible to define the ST as the moment from which we observe a particular microstructural transformation consisting of a massive formation of hydrates of the CSH type. The spectral analysis of the ultrasonic signal transmitted enables us to determine in terms of time, the maximum of the signal's amplitudes on a limited pass-bandwidth. This parameter seems representative of the evolutions of the concrete macrostructure and allows the determination of the setting time.