ABSTRACT
A common conclusion to all the investigations done about this subject is a generalized reduction of the mechanical and durability properties of the concrete with RA, with the increase of the substitution rate of natural aggregates (NA) with RA, when compared with concrete with NA only. The main objective of this study is the definition of procedures that allow the estimation of the properties of the concrete with recycled aggregates by knowing the density and the water absorption of the aggregates, natural and recycled, used in the production of the concrete. Another parameter for this estimation can also be the results of the compressive strength of the concrete at the age of 7 days. The influence of the aggregates properties in the behaviour of the concrete properties is commonly recognized by many authors. Limbachiya et al (2000), in their study about high-strength concrete with RA, refer, in the conclusion chapter, the relationship between the density and water absorption of the recycled and natural aggregates.
