Clear Asphalt Mixture for Wearing Course in Tunnels: Experimental Application in the Province of Bolzano

A new technical and political awareness on safety driving and reduction of environmental impact have increased the use of coloured asphalt pavements in road construction.A clear asphalt mixture (CAM) for wearing courses, designed and laid down during the rehabilitation of an Italian tunnel, was subjected to the acceptance inspection, mechanical characterization and determination of photometric properties. Traditional and performance-based tests were carried out to determine the failure resistance, compactability, stiffness, abrasion resistance and water sensitivity of the CAM. Luminance and reflection properties of CAM were measured and compared with those of HMA in order to assess possible lighting benefits.