Noise abatement in asphalt concrete pavements: Part 1. Non-destructive estimation of characteristic lengths using an impulse-echo approach

Treating asphalt concrete mixtures as porous viscoelastic media, an impulse -echo (I-E) non-destructive evaluation approach is presented to estimate th e viscous and thermal characteristic lengths of several asphalt concrete mi xtures within the rigid-frame and high-frequency limits of Biot's poroelast ic theory. Simulating a tyre-tread impulse on the pavement surface, this ap proach allows the independent evaluation of these characteristic lengths fo r each asphalt concrete mixture at ultrasonic frequencies from a single imp ulse-echo test. These characteristics lengths describe the fluid-solid fram e interactions and are related to the noise abatement characteristics of pa vements made of asphalt concrete mixtures. Other estimated material paramet ers include the quality factor, Q, the formation factor, F, tortuosity, tau (2). characteristic frequency fc, airflow resistivity, sigma, and permeabi lity kappa (0).