Mechanical impedance and CPX noise of SMA pavements

V.F. Vázquez , S.E. Paje

CPX noise is the sound measured in close proximity to the tyre/pavement contact patch when a vehicle is rolling. The mechanical impedance or dynamic stiffness of the pavement is one of the factors involved in the generation of this type of noise. The reduction of the impact noise generation mechanism can be achieved with the construction of mixtures with lower dynamic stiffness. On the other hand, SMA mixtures, widely used in Europe, have come into use recently in Spain as a surface layer. The aim of this work, carried out by the Laboratory of Acoustic Applied to Civil Engineering (LA2IC), is to establish a stiffness indicator of the bituminous mixtures according to European Standards. Thus, the dynamic stiffness has been studied in different samples, and the results have been compared with test made on different SMA core samples, which have been taken from an experimental road section. Dynamic stiffness was measured with an impact hammer, an accelerometer and a data acquisition system. Laboratory results have been analyzed in order to establish the accuracy of the method and the relationship with the CPX noise.

Mots clés: SMA mixture; CPX noise; dynamic stiffness; mechanical impedance

Domaines: Acoustique [physics.class-ph]

V.F. Vázquez, S.E. Paje. Mechanical impedance and CPX noise of SMA pavements. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810767⟩