Rapid and Continuous Imaging for Crack Monitoring During APT Experiments

Abstract

Accelerated pavement testing (APT) is well known as a very effective way to investigate the actual behaviour of pavement structures. Feedback from the test can be obtained in a couple of months through measurements and monitoring made during the experiment. Among them, pavement surface cracking is one of the most important parameters for the evaluation of experimental pavement performance. Generally, crack monitoring during APT tests is still carried out manually for every specific loading period. This classical approach is time-consuming and interesting information may be lost if a measurement is missed. For this reason, a Rapid and Continuous Imaging (RCI) technique has been developed and tested at IFSTTAR, for the monitoring of crack development on the pavement surface during APT experiments. The principle of this technique consists in taking images of the experimental pavement surface continuously along the test track, at intervals depending on the moving speed of the heavy traffic simulator, i.e. the road fatigue carrousel. A crack map, representing an overview of visible cracks on a pavement section can then be rapidly created using an ad hoc image processing tool. The application of this pavement crack mapping technique for crack monitoring on an asphalt pavement during a recent APT experiment showed interesting results.