Gradation influence on frost susceptibility of base granular materials

Abstract

Base granular materials are generally considered non-frost susceptible, which is an adequate assumption based on widely recognised frost criterions. However, their frost susceptibility is influenced by the presence of water that can unavoidably penetrate pavement structures. Even if unsaturated, freezing of unbound granular materials causes a net volume gain and an increase in water content which affect pavement performance during the spring period. This paper presents the results of a laboratory investigation on the effect of gradation on frost susceptibility, quantified with the segregation potential (SP), of three aggregate sources. The results suggest that SP values for all sources are strongly related to a fine particles state parameter. Moreover, the source influence was found to be described adequately with a parameter describing fine particles grain size distribution uniformity and fines specific surface. A model is proposed which combines gradation and mineralogical source effects on frost susceptibility of base granular materials.