Diagnosis of pavement structural damages using GPR: Fid-Bau Portal

Diagnosis of pavement structural damages using GPR

Benedetto, A. / Pensa, S.

Programmed policies for pavement management are needed because of the wide structural damage, that implies consequences for the safety and operability of road networks. In fact, during the last decade, road networks suffered from great structural damages of pavement, imputable to different reasons, such as the increasing traffic flow or the lack of means for routine maintenance. A local anomaly on the road surface can affect the safety of driving according to the use of the road, so it is possible to set up different restorations according to the different standards of road. Many damages, coming from the bottom layers and invisible until pavement cracks, depend on the infiltration of water and plastic soil that reduces greatly the bearing capacity of sub-asphalt layers. On the basis of an in-depth recent international literature overview, an experimental survey with Ground Penetrating Radar (GPR) was led to calibrate the geophysical parameters and to validate the reliability of an indirect diagnostic method of pavement damages. The experiments, discussed elsewhere, were set on a pavement where water was injected over a period of several hours: GPR travel time data were used to estimate the dielectric constant and the water content in un-bound aggregate layer, the variations in water content with time and particular areas where effective velocity of infiltration decreases. Otherwise, in this paper we want to pay a particular attention with a new method in order to invert the moisture map we obtained from GPR surveys. Since obtaining the distribution of permeability from GPR maps is a possible but difficult analytical process, we used a tool software to simulate the infiltration of water within unsaturated media. Here are shown the methodological process, correlated with the outcomes of the simulations.