Determinazione delle performance di un gonioriflettometro per la valutazione delle caratteristiche riflettenti del manto stradale

The present work is part of a research on road safety and aims to investigate the reflective properties of road materials to avoid glare, due to materials with a high degree of specularity, and phenomena of poor readability, caused by barely distinguishable materials. In order to evaluate the reflectance of the flooring, a laboratory gonioreflectometer was used and, starting from the results obtained, the average luminance coefficient Q0 and the specularity factor S1 were calculated. These parameters make it possible to classify road materials and consequently to design lighting systems properly. It is in fact important to evaluate the adequacy of the system not only in relation to the safety requirements towards the user, but also to respect the environmental requirements. In the second part of the thesis the possible link between the roughness of road pavements and the specular reflection component was investigated through the calculation of the average roughness Ra and of the mean profile depth (MPD). To do this, starting from a series of photographs, the upper surface of the bitumen carrots was reconstructed in 3D by a photogrammetric approach. The reflective properties of the materials, in this case four asphalt cores, were evaluated using the laboratory gonioreflectometer at the IFSTTAR site in Marne-la-Vallée, during an internship lasted four months. The results presented in this thesis apply in conditions of dry roads subject to public lighting.