High-resolution 3D geomatic techniques to assess hazardous spills impacts on road surface performances

Constantly growing people’s needs and industrial technologies cause the necessity to increase transport, which simultaneously increases the risk of accidents on the roads and spills of hazardous substances, including leakage of oil, hydraulic fluids, lubricants, and cargo spillage. These substances threaten the safety of road, all the road users and natural environments. Asphalt road surfaces are degraded by fuel or other liquid spillages; they can contribute to increase road surface material damage during vehicles trafficking. The effects of spilled substances on the road surface and consequently on the environment and user safety depend also on the exposure time. Due to the unpredictable of accidental situations and the positioning within the territory, there are situations that are managed at different time. Therefore, the exposure time become a fundamental parameter to be considered in the test to evaluate the different behaviors of road surface and the variation in danger over time. In this scenario, the research aims to evaluate the effects of hazardous liquid spilled from vehicles on the asphalt properties and related safety parameters by means of two combined high-resolution 3D geomatic techniques and over different exposure time. Geomatic techniques employed for the characterization of the asphalt samples belong to two different categories: active triangulation techniques (3D structured light projection scanner) and photogrammetric techniques (digital photogrammetry). These techniques are able to perform a three-dimensional modeling of the detected objects: a process that goes from data acquisition to the creation of a virtual 3D model. Products of these modeling should guarantee the maximum geometry accuracy and photo-realistic nature of the scanned objects. Some indicators have been extracted from high-resolution 3D models to study changes in asphalt performances due to the spillage of five different hazardous substances.