Properties of self-compacting concrete on fresh and hardened with residue of masonry and recycled concrete

• The residue of masonry is used in self-compacting concrete mixtures as an addition.
• The fresh properties of self-compacting concrete with recycled aggregate and residue of masonry were investigated.
• The use of recycled coarse aggregate in the production of self-compacting concrete is feasible.
• The incorporation of recycled aggregate cause a decrease in the mechanical properties (compressive strength and splitting tensile strength) of self-compacting concretes.

The present paper discuss the results of an experimental study about self-compacting concretes (SCC) made with recycled coarse aggregates and a mineral admixture obtained from a residue of masonry (RM). It was evaluated the effects of the use of the recycled aggregate on the properties of SCC. Five types of SCC mixes were tried, where the virgin coarse aggregate was substituted by the recycled aggregate between 0 and 100% by volume. The blended cement (Portland cement + admixture) remained constant at 480 kg/m3 and included 20% by weight of RM. The rheological properties of the fresh SCC were determined by means of slump and flow tests, V-funnel, and L-box tests. It showed appropriate workability and resistance to segregation, passing ability, and filling capacity. The mechanical properties were reduced with the incorporation of the recycled coarse aggregate due to the poor adhesion between the old mortar and aggregate; however, the results fall within admissible characteristics to be used in several constructive elements for its acceptable mechanical properties.