The effect of blending granular aggregates of different origin on the strength of concrete

► We present experimental results on granular systems. ► We give a physical characterization of grains used in concrete production. ► We determine the packing density and specific surface area for different mixtures of grains. ► We study the behavior of the strength of concrete cores as a function of the grain mixtures. ► We present a description of the two competing effects intervening in the strength response.