Assessing Hazardous Spills Impact on Road Surface Performances by 3D High Resolution Surveying Techniques

Surface texture of a road pavement is recognized as one of the most relevant parameters in driving safety. Spillages on the highway can lead to dangerous conditions for road users and cause damage to the road surface. Hazardous substance spills caused by traffic accidents threaten the safety road and request a specific clearance operation to reduce the risk of asphalt surface degradation. The aim of this paper is to evaluate the effect of usual hazardous liquids spilled during traffic accidents from vehicles on the asphalt properties and related safety parameters. The experimental application is performed via digital photogrammetry. The application of 3D geomatic techniques allows to calculate new texture indicators through geometric and colorimetric information more accurate than traditional survey techniques. The proposed approach can constitute a new useful investigation method, in addition to traditional surveys, which are slower and less precise. The texture reading by using three-dimensional analysis is an innovative way to obtain and compare the traditional performance indicators used to measure friction with new proposed indicators. In particular, the described experience evidences the mechanical behaviour and the structural damage of asphalt samples related to different exposure times treated with five hazardous liquids. Both traditional and innovative techniques are carried out to evaluate roughness (British Pendulum Number, BPN). The obtained results show how the various substances affect in different way the samples asphalt surface.