RU2519313C1 - Complex additive - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: complex additive for gypsum-cement-pozzolan binder contains a superplasticiser that moderates setting - plasticiser BEST-TB and carboxylate polyether Odolit-K at the following ratio of components, wt %: plasticiser BEST-TB 25-75; carboxylate polyether Odolit-K 25-75.

EFFECT: moderation of kinetics of initial structure formation of gypsum-cement pozzolan systems with preservation of their high end strength, increased coefficient of softening.

1 ex, 1 tbl

Description

The invention relates to the field of construction, namely to complex additives for building mixtures on gypsum-cement-pozzolanic binders and can find application in the manufacture of building products and structures.

A well-known complex additive for building mixtures containing sodium or potassium ethyl silicate and / or sodium or potassium methyl silicate, carboxylate polyester and water (RU 2351560, 10/22/2007).

The disadvantage of this additive is the high speed of the initial structure formation of gypsum-cement-pozzolanic systems.

Known complex additive for concrete mix containing carboxylate polyester, an organosilicon component and a hardening accelerator (RU 2457190 C1, 07.27.07.2012).

The disadvantage of this additive is the high speed of the initial structure formation of gypsum-cement-pozzolanic systems.

The closest is a complex setting retardation additive containing a superplasticizer based on polymethylene naphthalene sulfonates (PNS) and technical drug lignosulfonates with a mass ratio of 1: (0.33-3) (RU 2262490 C2, 05/10/2005).

The disadvantage of this invention is the low water-reducing effect of the specified plasticizer and a slight reduction in the time of the initial structure formation of gypsum-cement-pozzolanic systems.

The objective of the present invention is to slow down the kinetics of the initial structure formation of gypsum-cement-pozzolanic systems.

The technical result consists in lengthening the setting time of building mixtures based on gypsum-cement-pozzolanic binder based on low-grade gypsum while maintaining their high final strength and increasing softening coefficient.

The result is achieved in that a complex additive for a gypsum-cement-pozzolanic binder containing a setting retardant superplasticizer, according to the invention, contains a BEST-TB plasticizer as a retarder and additionally contains an Odolit-K carboxylate polyester in the following ratio of components, wt.% :

plasticizer "BEST-TB" 25-75;

Odolit-K carboxylate polyester 25-75.

As components of the proposed complex additives use:

- plasticizer "BEST-TB", manufactured by LLC "Innovative Technologies". “BEST-TB” refers to the superplasticizers of the first group and is a copolymer based on carboxylic acid esters with the addition of a dark brown phosphate component with a density (at 20 ° C) of 1.24 g / cm3, mass fraction of dry matter 20-30% ;

- carboxylate polyester "Odolit-K", TU 5745-01-96326574-08.

The carboxylate polyester produced by Service-Group LLC was used as part of a complex additive.

The additive is prepared by mixing these components.

The invention is illustrated by the following example.

For the preparation of samples used gypsum-cement-pozzolanic mixtures based on gypsum G6BP manufactured by Arakchinsky Gypsum LLC (GOST 125-79), pozzolanic component - active mineral additive (AMD) (industrial waste from the metallurgical industry) - ferrosilicon, ground to a specific surface of 391 m / kg, Portland cement ПЦ500 Д0 Н of the Volsky plant, in the following ratio (parts by weight):

gypsum: Portland cement: AMD = 80: 19: 1.

The complex additive was introduced into a gypsum-cement-pozzolanic mixture with mixing water in the form of an aqueous solution in the amount of 1-1.5% by weight of the binder. The optimal content of the complex additive for the gypsum-cement-pozzolanic mixture indicated as an example is 1.5% by weight of the binder.

The aqueous solution was added to the gypsum-cement-pozzolanic mixture until normal density was achieved according to GOST 23789-79.

From the gypsum-cement-pozzolanic mixtures, beam samples with the dimensions 4 × 4 × 16 cm were made.

After 28 days of normal hardening, the samples were subjected to mechanical tests. The strength of the samples was determined in accordance with GOST 23789-79.

The compositions of the complex additives and the results of mechanical testing of the samples are given in table 1.

Tests were also conducted samples without additives and with the addition of the prototype. The water-binding ratio of the composition without the additive was 0.54, with the proposed complex additive - 0.35-0.42, with the addition of the prototype - 0.48.

Table 1 No. p.p The content of components in the additive, wt.% The content of complex additives,% by weight of binder W / T Setting time, min Rizg, MPa Rszh, MPa K _p Carboxy Plate Polyester Best TB Start the end one - - -

5 8 7.68 18.03 0.41 2 75 25 one

9.5 11.5 8.62 21.1 0.53 3 25 75

40 43 8.3 20.5 0.51 four one hundred 0

5 7 10.58 28.00 0.62 5 75 25

24 26.5 9.81 22.48 0.68 6 fifty fifty 1,5

56 61 8.92 22,20 0.66 7 25 75

64 69.5 8.84 22.13 0.54 8 0 one hundred

198 223 8.33 22.50 0.53 9 (prototype) 1,5

16 19.5 8.25 19.9 0.49 Note *: above the line is the average value of the indicator; below the line is the relative value of the indicator in% of the control.

From table 1 it can be seen that the gypsum-cement-pozzolanic mixtures modified with the proposed complex additive have a delayed kinetics of the initial structure formation, which is expressed in lengthening the time of their setting. Samples made from gypsum-cement-pozzolanic mixtures modified with a complex additive have a high final strength and an increased softening coefficient.

Claims (1)

A complex additive for a gypsum-cement-pozzolanic binder containing a setting retardant superplasticizer, characterized in that it contains a BEST-TB plasticizer and an additional Odolit-K carboxylate polyester as a retarder, in the following ratio, wt.%:
plasticizer "BEST-TB"25-75;
Odolit-K carboxylate polyester 25-75.