RU2360879C1 - Complex additive - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: complex additive contains components at the following ratio, wt %: superplasticiser - sodium polynaphthalene methyl sulfonate 30-45, defoaming agent - Troykyd D128 - 0.25-0.50, sodium thiosulfate - the rest.

EFFECT: higher strength of 12-hour concrete.

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Description

The invention relates to the composition of a complex additive for concrete mix and mortar.

A well-known complex additive for building mixtures, including relaxol - a mixture of ballast salts of coke oven gas desulfurization based on sodium thiosulfate and thiocyanate, technical lignosulphates and C-3 superplasticizer in the following ratio, wt.%: Relaxol - 20-50, technical lignosulphates - 20- 40, superplasticizer C-3 - the rest (RU No. 2290375, С04В 22/08, С04В 24/24, С04В 24/18, С04В 103/61, publ. 12/27/2006).

This complex additive does not ensure the achievement of the transfer strength of concrete at the age of 12 hours.

The closest in technical essence and the achieved technical result to the claimed additive is a complex additive containing wt.%: Silicon organic defoamer - 0.02-0.06, superplasticizer S-3 - sodium polynaphthalene methyl sulfonate - 0-40, sodium thiosulfate - 40- 55, superplasticizer-lignopane - 10-20, sodium carbonate - 1-2 (RU 2247092 C1, 02.27.2005, 4 pp.).

The known additive also does not ensure the achievement of the transfer strength of concrete at the age of 12 hours under normal humidity conditions of hardening.

The basis of the invention is the task of creating a complex additive in concrete mixtures and mortars, which ensures the achievement of the transfer strength of concrete at the age of 12 hours and allows you to switch to the steam-free technology for the production of precast and reinforced concrete.

The problem is solved in that the complex additive, including a superplasticizer - sodium polynaphthalene methyl sulfonate, antifoam and sodium thiosulfate, contains Troykyd D128 as an antifoam in the following ratio, wt.%:

Specified Superplasticizer 30-45 Specified Antifoam 0.25-0.50 Sodium thiosulfate rest

Between the totality of the essential features of the claimed invention and the achieved result, there is a causal relationship.

Sodium polynaphthalene sulfonate is adsorbed on Portland cement hydration products, primarily on ettringite, and slows down the conversion of ettringite to calcium monosulfoaluminate, which has a blocking effect in the early stage of hydration and leads to an increase in the duration of the induction period. Since the formed system of conditionally closed pores is heterogeneous and contains a significant number of pores larger than 500 microns, at the early stage of hardening, a decrease in the uniformity of the structure of cement stone is accompanied by an acceleration of cracking processes under load and a decrease in compressive strength. The antifoam based on vegetable oils Troykyd D128 prevents the involvement of unorganized air and in the optimal dosage does not reduce the water-reducing effect of the superplasticizer. In combination with sodium thiosulfate, the inventive complex additive ensures that the concrete has a transfer strength of 12 hours without heat and moisture treatment or with heat and moisture treatment at a temperature not exceeding 40 ° C.

At the time of application, according to the authors, the claimed complex additive is unknown and has a world novelty.

The inventive combination of essential features exhibits a new property that allows you to get the specified technical result.

The claimed invention is industrially applicable and can be used in the production of concrete, mortar.

For the preparation of complex additives used

sodium polynaphthalene methyl sulfonate - disperson No. 9505 (registration number C.A.S - 9084-06-4), sodium thiosulfate (GOST 27068-86), antifoam Troykyd D128 based on vegetable oils (US 5685898, 11.11.1997). Sodium thiosulfate was ground and mixed with the remaining components in the claimed percentage.

To study the properties of the inventive additives, concrete mixtures with a hardness of 5-7 seconds were prepared, containing 470 kg / m ^{3 of} cement, granite crushed stone of the Kuznechnoye deposit, fractions 5-20 and river sand with a particle size 2.2. For the preparation of the concrete mixture used cement Oskol cement plant brand PTs-500D0.

The inventive additive was previously dissolved and introduced into the concrete mixture together with mixing water in an amount of 0.8-1.2%. In the obtained concrete mixtures, the stiffness was determined according to GOST 10181-2000. Concrete samples were prepared from concrete mixtures for testing for early strength. The samples hardened at a temperature of 30 ° C at 100% humidity and at the age of 12 hours were tested for compressive strength according to GOST 18105-86. Tests were also conducted concrete mixture made in accordance with the prototype, as well as concrete mixture containing 0.375% by weight of cement dispersed concrete No. 9505 (experiment No. 5 in the table). The results of the tests are presented in the table.

The table shows that the inventive additive according to the invention at the age of 12 hours, the achievement of the transfer strength of concrete (32 MPa), while maintaining the rigidity of the concrete mixture (experiments 2-4).

This complex additive allows the introduction of steamless and low-warming technology for the production of precast concrete and reinforced concrete at prefabricated concrete plants.

Claims (1)

A complex additive comprising a superplasticizer - sodium polynaphthalene methyl sulfonate, antifoam, sodium thiosulfate, characterized in that it contains Troykyd D128 as an antifoam in the following ratio, wt.%:
Specified Superplasticizer 30-45 Specified Antifoam 0.25-0.50 Sodium thiosulfate Rest