ABSTRACT
The main GPR applications in pavement engineering include the detection of voids underneath pavements (Lau et al. 1992), the evaluation of layers thicknesses (Al-Qadi & Lahouar 2004), delamination of concrete (Derobert et al. 2009, Kalogeropoulos et al. 2013) and reinforcing bars detections (Hugenschmidt & Loser 2008, Huston et al. 1999), the location of utilities (Ayala-Cabrera et al. 2011), asphalt stripping monitoring (Scullion et al. 1994), and bridges inspections (Benedetto et al. 2012b). Many efforts have been also devoted to the monitoring of volumetric water content in pavement structures (Al-Qadi et al. 2004) and in typical subgrade soils (Grote et al. 2003, Benedetto 2010, Benedetto & Tosti 2013b, Benedetto et al. 2013, Lambot et al. 2004b, Tosti 2013). On the other hand, recent researches have dealt with the GPRbased evaluation of clay content in soils causing plastic deformation behaviors (Patriarca et al. 2013, Tosti & Benedetto 2012, Tosti et al. 2013),
1 INTRODUCTION
In the last few years the effects of the Global Economic Crisis are reshaping the strategies of economic and financial resources investment in many fields of engineering and applied sciences, particularly focusing towards the best allocation of funds in rehabilitation and maintenance processes. In pavement engineering, such need for an efficient and effective management of economic resources should also challenge to stem the crucial issue of high social costs due to road accidents. In that respect, the conditions of road pavements play a key role in driving safety as frequent primary causes of accidents. To cite a few instances: lowering of friction, deformation of pavements causing surface ponding of water and resulting cracks that induce dynamic effects on vehicles, increase the possibility of accident occurrences. Such framework outlines the importance of an effective programmed plan for pavement management in order to obtain a long-term durability of operations with the main goal to remove the causes of damages. In that respect, rehabilitation processes of road infrastructures are increasingly being dealt with the use of non-destructive techniques.
