Concrete with mixed recycled aggregates: Influence of the type of cement

This paper focuses on the use of mixed recycled aggregates (MRAs) as coarse aggregate or fine fraction in concrete and the influence of the cement used. Four mixes suitable for manufacturing low-strength concrete and three mixes for medium-strength precast elements were studied. Type CEM II, CEM III/A and CEM V/A cements were used, the last two being sulphate-resistant cements containing blast furnace slag. Compressive, tensile and flexural strength properties decreased as the proportion of MRA increased. Compared with CEM II cements, the strength and permeability of the concretes made with sulphate-resistant cement decreased less as the amounts of MRA increased.

► Real mixed recycled aggregates (MRAs) produced in a treatment plant were used.
► Twenty four different concretes made with CEM II, CEM III/A or CEM V/A cements were tested.
► Compressive, tensile and flexural strength decrease when the MRA amount increases.
► Concretes with CEM III or V showed a lower decrease in strength and permeability.
► Preliminary results on the use of MRA fine fraction show an acceptable behaviour.