HMA COMPOSITION VS. SURFACE CHARACTERISTICS: ISSUES AND PERSPECTIVES TO OPTIMISE ROAD ASSET MANAGEMENT

As is well known surface characteristics (texture, friction, reflectivity, roughness) greatly affect road safety. As a matter of fact, accident ratio in wet conditions depends both on texture and friction. Further, surface properties are a vital property of the road in many road conditions and affect maintenance and rehabilitation activities. Although such relevance, the prediction of surface properties based on hot mix asphalt (HMA) bituminous mix composition and construction still calls for further research. Indeed, there is not a clear framework for a mix design oriented to surface properties. In the light of the abovementioned facts authors’ efforts were focused into the analysis of literature on the topic and the proposal of a conceptual framework for the derivation of surface properties based on mix composition. Many experiments were planned and carried out in order to obtain information on method suitability. Although other experiments are needed, results confirmed that some of the proposed models are well-grounded in logic and can be considered a first step in the aim of formalizing an algorithm able to give practical answers to the abovementioned issues.