METHOD OF MANUFACTURING STRUCTURES AND PRODUCTS FROM CONCRETE MIXES Russian patent published in 1997 - IPC

FIELD: manufacture of building materials. SUBSTANCE: invention aims at diminishing sticking of metal parts of process equipment located in immediate contact with surface of concrete mixes and concretes. To that aim, presence of sodium and/or potassium carbonate in concrete mix is necessary because these salts, experiencing action of constant current passed through concrete mix or concrete, give rise to formation of gas interlayer in the electrode zone. Concrete is treated by constant current at strength 10-60% R₂₈ for a period of time determined from relationship: T > 4R/DiP where R is strength of concrete, %R₂₈; D content of sodium and/or potassium carbonate contained in mix, % on weight of tempered water; i density of constant current, A/sq.cm; and P liquid constituent intake, l/cu.m. Concrete mix treatment time in its laying stage is determined from relationship: T > 20/DiP. Invention, in particular, eliminates sticking of metal mounting to surface of concrete structures and products being molded and, in winter time, additionally reduces heat loss when structure is cooled. When concrete mix is transported or laid, invention prevents sticking of mix to tiplorry basket, body of rotatory skip, and vibrator, and also alleviates the problem of laborious manual cleaning of electrodes when pre- heating concrete mixes. EFFECT: facilitated handling of concrete mixes. 2 cl