A PROCESS FOR THE PREPARATION OF A PUMPABIE AND SPRAYABLE CONCRETE MIX AND AN AIRPIACING UNIT FOR PREPARING THE SAID CONCRETE MIX

• Main Authors: MULLER KARL-HANS, BARTHEL WALTER
• Format: Patent
• Language: English
• Published: 26.10.1991
• Edition: 5
• Subjects: APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; ARTIFICIAL STONE; ATOMISING APPARATUS; BUILDING; BUILDING IMPLEMENTS OR OTHER BUILDING AIDS, OR THEIRUSE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; CONVEYING; FIXED CONSTRUCTIONS; FORMS; HANDLING BUILDING MATERIALS ON THE SITE; HANDLING THIN OR FILAMENTARY MATERIAL; LIME, MAGNESIA; METALLURGY; NOZZLES; PACKING; PERFORMING OPERATIONS; PNEUMATIC TUBE CONVEYORS; PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL,e.g. PLASTER; REFRACTORIES; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTINGBUILDINGS; SCAFFOLDING; SHOP CONVEYOR SYSTEMS; SHUTTERING; SLAG; SPRAYING APPARATUS; SPRAYING OR ATOMISING IN GENERAL; STORING; TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING ORTIPPING; TRANSPORTING; TREATMENT OF NATURAL STONE; WORKING CEMENT, CLAY, OR STONE

To apply a layer of spray concrete to a surface, a pumpable and sprayable spray concrete mix is made up from cement, aggregates, if appropriate additives, and water. A preset mass flow of the spray concrete mix is sprayed by means of a concrete delivery pump through a concrete transfer line to a spray gun with a device for introducing propellant air under a delivery pressure of several bar. The propellant air is laden with synthetic silica having a BET surface area of at least 25 m /g. With the propellant air, the synthetic silica is introduced into the mass flow of the spray concrete mix in such a quantity that the applied spray concrete undergoes a spontaneous temperature increase by a few degrees Kelvin immediately after the application. A spray gun for the process is also described.