Active infrared thermography applied to defect detection and characterization on asphalt pavement samples: comparison between experiments and numerical simulations

Abstract

This work is devoted to the application of active infrared thermography to defect detection in pavement structures. The challenge is to localize and to determine some properties of defects (e.g. shape and depth) into a highly heterogeneous material. Experimental work was carried out in laboratory conditions using a pavement sample containing two defects (wood and air). Pulsed thermography results were compared with FLUENT numerical simulations. Different preliminary approaches were investigated to analyze data: singular value decomposition of infrared image sequences, contrast image methods and computation of thermal effusivity considering a heat transfer model in a semi-infinite material. This last method is more sensitive to experimental conditions such as the presence of natural convection at a sample surface. However, all methods allow detection of one defect into the pavement sample.