The use of Construction and Demolition aggregate in unbound sub-base and bituminous bound road base

This paper presents the results of an investigation, conducted at the University of Padova Road Research Laboratory, to verify the suitability of aggregates from construction and demolition work (C&D: bricks, concretes, etc.) in the formulation of unbound mixes for sub-bases, and bituminous mixes for base layers of road and airport pavements. The unbound mix samples were prepared using both the Proctor methodology and a gyratory compactor, usually used for the mix-design of bituminous concretes, in order to verify the suitability of the unbound materials. The gyratory press was also used for the formulation of the bituminous mixes, together with the classical Marshall methodology. In both cases, sample compaction with the gyratory technique provided useful information on the shear strength of the mixes and density trend of the material during compaction.