Bituminous mixes: The materials that make up bituminous mixes or asphalts are basically aggregates (fine, coarse and filler) and a bituminous binder. The role of Micronized Calcium Carbonate, which acts as filler, forming part of the aforementioned fraction of fine aggregates, is crucial. It has been demonstrated that according to the size of the particle and its specific surface, the quantity of bituminous binder to be added varies. This not only affects the cohesion of the mix but also its wáter repelling properties.