Sensing road pavement health status through acoustic signals analysis

Traffic produces seismic and acoustic waves. These waves affect both bystanders and civil infrastructures in terms of health issues and of complication in the maintenance, rehabilitation, assessment and monitoring processes, respectively. Therefore, it is increasingly important to reduce, or at least to monitor these annoyances through methods that are capable to take advantage of the potentialities offered from new technologies. The aim of this study is to present the preliminary results of the application of a new method for the monitoring the traffic-induced vibrations and noise, and for the assessment of the health conditions of road pavements. This method can be classified as an acoustic method because it is based on the concept of acoustic signature, defined in this work as the spectral content of the acoustic signals coming from the road pavement under vehicular traffic condition. The estimation of variation over time of this signature provides important information about the changes of the response of roads to the traffic, i.e. about their structural health conditions. In this preliminary stage, acoustic signals were detected through a sensor placed in a hole drilled both in un-cracked and cracked slabs of asphalt concrete, during accelerated loading in-lab tests (EN 12697-22:2007). Simultaneously, these signals were sampled and processed in order to carry out the acoustic signature of the slab under test. Results show the possibility of developing a new acoustic method that allows estimating the structural health condition of a road pavement from its acoustic signature.