Influence of the use of recycled concrete aggregates from different sources on structural concrete

• Source of recycled concrete aggregates (RCA) highly influences concrete properties.
• RCA from medium/high strength concrete have little influences on concrete properties.
• Lab-sourced RCA are equivalent to equal strength precast elements-sourced RCA.
• This proves the reliability of previous researches made with lab-sourced RCA.

This paper intends to evaluate the capacity of producing concrete with a pre-established performance (in terms of mechanical strength) incorporating recycled concrete aggregates (RCA) from different sources. To this purpose, rejected products from the precasting industry and concrete produced in laboratory were used. The appraisal of the self-replication capacity was made for three strength ranges: 15–25 MPa, 35–45 MPa and 65–75 MPa. The mixes produced tried to replicate the strength of the source concrete (SC) of the RA. Only total (100%) replacement of coarse natural aggregates (CNA) by coarse recycled concrete aggregates (CRCA) was tested. The results show that, both in mechanical and durability terms, there were no significant differences between aggregates from controlled sources and those from precast rejects for the highest levels of the target strength. Furthermore, the performance losses resulting from the RA’s incorporation are substantially reduced when used medium or high strength SC’s.