Integrated road pavement survey using GPR and LFWD

Ground Penetrating Radar is frequently used for inspection the road pavement. Many applications are carried out: from pavement's layer thickness estimation, to damage detection and diagnosis, from the evaluation of geotextile effectiveness to the assessment of the bridge decks. Here we propose to integrate GPR survey with the Light Falling Weight Deflectometer. LFWD is a portable instrument that is used for measuring the Young Modulus through the analysis of the propagation of elastic waves in the pavement structure. The point of strength of this approach is that it is possible to correlate geometrical and some physical characteristics, in this case dielectric constant, of pavement layers, extracted from the GPR maps, to the mechanical properties, such as young modulus, measured using LFWD. It is well known that from a GPR stand alone survey is not possible to have directly any information about the mechanical characteristics of the structure. Otherwise, following this integrated method it is possible to reach a more comprehensive description of the road pavement. This diagnostic tool for pavement damage investigations seems absolutely very promising, cost effective and efficient in its implementation. Finally two case studies are presented: the first over about 3000 m of a real pavement the second over an unpaved airport strip.