The results of the investigation of the structure of the concrete, modified by the additive expanding, on the combined aggregate, which is a natural crushed stone mixed with crushed concrete, are presented. The study of the properties and regularities of the formation of the concrete structure is simultaneously a method of controlling their production. Regularities and reasons for the change (decrease) in the quality indices of concretes with a combined aggregate are established. Investigation and normalization of the properties of concretes on combined aggregates will allow using them along with traditional structural concrete.

Keywords: recycling, combined filler, contact area, structure, defects, durability