CS232022B1 - Liqufying mixture agent for concrete and anhydrite mixtures - Google Patents

Description

( ⁵⁴ ) Liquefied blend additive of cement and anhydrite mixtures

The fluidized admixture of cement β anhydrite mixtures is intended to improve the processability of these mixtures even at low water coefficients. The additive is preferably metered into the prepared cementitious or anhydrite mixture in an amount of 0.1 to 1.0% by weight of its dry matter. The liquefaction additive of the present invention is characterized in that the additive consists of a mixture of salts of dinaphthylsulfonic acid and a sulfonated condensate of divalent phenols and formaldehyde and -naphthol, the dry weight ratio of the two in the additive being 1: 0.05 to 1: 1.

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232 022

BACKGROUND OF THE INVENTION The present invention relates to a fluidizing additive for efficiently increasing the processability of cementitious and anhydrite mixtures, in particular slurries, mortars and concrete mixtures, particularly in the preparation and processing of cast concrete and grout. The fluidizing additive makes it possible to produce mixtures with a relatively low water coefficient which can be prepared with lower amounts of binders, i.e. cement or anhydrite.

A number of additives are currently being produced and used to improve the processability of cementitious or anhydrite mixtures.

The simplest substances used for this purpose are treated waste products from chemical production, for example additives based on ligninsulfonates or dinaphthyl disulfonates. Substances manufactured intentionally for this purpose have a higher liquefaction effect, among which compounds based on melamine-formaldehyde resins, whose prices are, however, several times higher compared to treated waste products.

It is an object of the present invention to provide a plasticizing additive composition formed from waste products, but having the highest possible liquefaction effect.

This object is achieved by a fluidising additive according to the invention intended to increase the processability of cement and anhydrite.

232 022 mixtures, characterized in that it consists of a mixture of salts of dinaphthyldisulphonic acid and a sulphonated condensate of divalent phenols with formaldehyde and 4-naphthol, the weight ratio of both in the mixture being 1: 0.05 to 1: 1 in the dry matter .

The liquefaction additive of the invention, added to the cement or anhydrite mixture in an amount of 0.1% to 1.0% of its dry weight to the cement or anhydrite content of the cement or anhydrite mixtures, effectively increases their processability, the liquefaction achieved being substantially greater than the addition the salts of dinaphthylsulfonic acid or sulfonated divalent phenol condensate with formaldehyde even in larger doses.

The mixed liquefaction additive according to the invention is suitable for the preparation of in particular liquid mixtures with a cementitious binder, since the effect achieved is not only to increase the processability and fluidity of the mixture but also to partially aerate the mixture which prevents mixing of the individual components in the liquid state. the transport time of the mixture and its processing until the binder component solidifies. Therefore, its favorable effect is manifested especially in cast so-called self-leveling floor concretes with cement or anhydrite binder.

In an exemplary embodiment, a mixed liquefaction additive according to the invention was prepared containing 1% by weight of dry matter of 1% sodium salt of sulfonated naphthenic acid sodium dinaphthyl disulfonate and 0.5% of sulfonated divalent phenol condensate with phenolformaldehyde and $ -naphthol. This liquefying compound was added to the prepared cementitious compound

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232,022 mixtures; for comparison, the cement mix was prepared in two variants, the first mix containing 400 kg of Portland PC 400 cement per 1 m volume, 1750 kg of mined aggregate up to 16 mm and 220 liters of water, while the second mixture contained 400 kg of SPC 250 slag-portland cement. 1750 kg of mined aggregates up to 16 mm and 220 l of water. For both mixtures the water coefficient w was ~ 0.55. The workability of both mixtures, to which 0.5% dry solids of the present invention were added, was measured by settling the standard cone of the mixture, which was 24 cm for the first mixture and 21 cm for the second mixture. The workability of both cementitious mixtures without liquefaction additives was considerably worse, as the standard cone of the mixture was measured to be only 1.5 and 2.5 cm, respectively. The increase in processability with the additive of the invention was more effective than the other additives, for example both mixtures with 0.5% dry matter of sodium dinaphthyl disulfonate had a standard cone settlement of 17.5 cm and 14.0 cm, respectively, with 0.5% dry matter of melamine formaldehyde condensate. the standard cone settlements had 20.0 cm and 10.5 cm, respectively.

The composite additive according to the invention is particularly suitable for the preparation of a concrete mix for the production of thin-walled precast concrete in vertical molding machines, since it makes it possible to reduce the water coefficient of the mixture from w = 0.7 to 0.8 to w - 0.5 to 0.6. significantly reduce cement consumption.

The liquefaction additive should only be added after the main ingredients of the mixture have been mixed, since its effectiveness is highest when dosed as the last ingredient of the mixture.

Claims (1)

SUBJECT OF THE INVENTION 232 022 A liquefying admixture of cement and anhydrite mixtures, dosed in an amount of 0.1 to 1.0% of its dry weight to the cement or anhydrite content by weight of the mixture, characterized in that it consists of a mixture of dinaphtylsulfonic acid salts and sulfonated condensate of divalent phenols with formaldehyde; β naphthol, wherein the dry weight ratio of the two in the mixed additive is 1: 0.05 to 1: 1.