Thermal non-destructive characterisation of layers detachment in the roadways

In this work, we present numerical simulations, in 3D, which aim at studying the aptitude of the thermal non-destructive testing to detect the detachment of layers of two roadways structures: semi-rigid and thick. We will study the defect geometry influence of the separation type between the layers on the simulated thermographical image on the surface. For that, we will consider two parallelepipedic roadways structures, of the same dimensions; the first one is of semi-rigid type and the second one is thick. These structures are excited by a heat flux on the surface, the opposite face being maintained at a constant temperature and other surfaces are thermically isolated. Separation between two layers of the roadway is materialised by the insertion of an air blade. Once steady operation is established, we will take and study the thermographical image on the surface. This study is carried out using numerical commercial computation software, based on the finite element method.