Abstract
Challenges in finding high-quality sources of natural aggregate have led Saskatchewan, Canada, road agencies to explore alternative solutions to meet aggregate demands. The use of recycled materials, such as recycled portland cement concrete (PCC), though traditionally limited to low-quality applications such as subbase or backfill materials, shows promise as a technically viable solution that also offers economic and environmental advantages. In this study, mechanistic material testing was used to examine the effects of cement stabilization on traditional granular base and on two impact-crushed recycled PCC materials from different locations. The unstabilized PCC materials had substantially better mechanistic material properties than the unstabilized conventional granular base material; this result indicates that PCC materials could be suitable for use in high-quality applications, such as base course layers, rather than being limited to use in low-quality applications, such as utility and embankment fills. This study also showed that cement stabilization substantially improved the mechanistic properties of conventional granular base material, yet had a much less pronounced effect on the material properties of the PCC materials. This result may be attributable to poor absorption of the cement by the PCC or a lack of rehydration of the PCC. There was minimal variability in the mechanical behavior of the PCC specimens despite a difference in stockpile location. Both types of PCC material were processed and crushed with the same technique and equipment.