Abstract: A method wherein the extraction of a quantity of sand, with a granular size and distribution ratio, are subjected to a moisturing or dewatering treatment until a moisture content of a maximum of 15% m/m is attained; supplying and/or storing in bulk of an aggregate, such as fly-ash, with a smaller granular size than that of the sand fraction; and feeding and mixing the sand fraction and aggregate by means of a through-flow process, the mixture being poured or delivered so that a base material for mortar will have an optimal grain size distribution ratio and homogeneous composition.