ABSTRACT
ABSTRACT: This paper is focused on the expansive properties of reclaimed asphalt pavement (RAP) that may be used as pavement base materials in the state of Illinois. Different recycled hot mix asphalt materials were evaluated for use as aggregates in unbound pavement layers by assessing the differences in expansion potentials between recycled and virgin aggregates. Significant expansion levels have been found for RAP materials containing high percent of steel slag aggregates. This expansion has been attributable to hydration of the calcium and magnesium oxides in the recycled steel slag aggregate when exposed to water. The results of the expansion tests suggested the use of RAP materials containing high percentages of steel slag aggregates may have to be avoided in the pavement substructure layers depending upon the level of expansion.
