Concretes with aggregates from demolition waste and silica fume. Materials and mechanical properties

The purpose of this paper is to provide new data related to the field of recycled concrete in Spain. In keeping with this, several procedures were established, on the basis of which conclusions have been drawn regarding the suitability or non-suitability of recycled aggregates in Spain. Standard tests were carried out to determine the density, water absorption, grading, shape index, flakiness index and fragmentation resistance. Subsequently, proportion parameters were defined for average performance fresh and hard concrete made with these aggregates. These parameters were used to produce conventional concrete (CC) and conventional concrete with silica fume (CCS). The mixes were then adjusted for the production of recycled concrete (RC) and recycled concrete with silica fume (RCS) both containing 50% recycled coarse aggregates. Tests were conducted to determine the properties—both physical (density and water absorption) and mechanical (compressive and tensile splitting strength and static modulus of elasticity).