DRY MIXTURE FOR THE PREPARATION OF CONCRETE, FRESH CONCRETE AND METHOD FOR THE PREPARATION OF FRESH CONCRETE

摘要

The present invention relates to fresh concrete which contains in 1 m³50 to 300 kg of water, 135 to 400 kg of cement or 135 to 600 kg of a mixture of cement and at least one substituent thereof, 10 to 150 kg of finely ground brick, ceramic, mixed or concrete recyclate having a particle size of 5 to 250 microns and a specific surface of 300 to 1500 m²/kg or 10 to 150 kg of a mixture of finely ground brick, ceramic, mixed or concrete recyclate having a particle size of 5 to 250 microns and a specific surface of 300 to 1500 m²/kg and microsilica and/or at least one substituent thereof, with a content of finely ground recyclate in this combination of at least 10 % by weight, and 1000 to 2300 kg of aggregate. 45 to 100 % of the aggregate is composed of recyclate from inert construction and demolition waste, 0 to 40 % of the aggregate consists of natural aggregate and 0 to 40 % of aggregate consists of lightweight artificial aggregate and/or cinder and/or scoria and/or polystyrene and/or at least one organic filler and/or another component for improving thermal and/or acoustic and/or fire resistance properties of hardened concrete. The aggregate grains are coated and their pores are filled with finely ground brick, ceramic, mixed or concrete recyclate or with a mixture of finely ground brick, ceramic, mixed or concrete recyclate and microsilica and/or of at least one substituent thereof and the cement paste is adhered to the aggregate particles thus treated. In addition, the invention relates to a dry mixture and a method for the preparation of this concrete.