RU2553795C2 - Complex additive for heavy concrete mixtures - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the composition of a complex additive. A complex additive for heavy concrete mixtures, which includes technical lignosulphonates and montmorillonite-containing clay, further contains a deactivated catalyst for dehydrogenating cyclohexanol from ε-caprolactam production and a product of combined dispersion to particle size smaller than 10^-2 mcm of montmorillonite-containing clay and ε-caprolactam in ratio of 1/0.5 and castor oil and technical hydrogenated fat in ratio of 1/1, with the following ratio of components, wt %: technical lignosulphonates 63-70, deactivated catalyst for dehydrogenating cyclohexanol from ε-caprolactam production 5-7, montmorillonite-containing clay 16-18, ε-caprolactam 8-9, castor oil 0.5-1.5, technical hydrogenated fat 0.5-1.5.

EFFECT: longer periods for the beginning and end of hardening heavy concrete mixtures, high ultimate compression strength of the concrete, high consistency of the concrete mixture and low water absorption of the concrete.

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Description

The invention relates to the construction industry, and in particular to the composition of additives for heavy concrete mixtures.

A complex additive is known for heavy concrete mixtures based on technical lignosulfonates and waste production of caprolactam bottoms product of a trichlorethylene regeneration column (see RF patent No. 2209792, C04B 28/02, 2002). According to the invention, the additive contains, wt.%:

VAT product of the column for the recovery of trichlorethylene - 40-90

Technical lignosulfonate - 10-60.

This additive has low wetting and dispersing properties, which impairs the quality of mixing concrete mixtures.

This disadvantage was overcome in another well-known complex additive for heavy concrete mixtures, including technical lignosulfonates and clay containing montmorillonite. (see RF patent No. 2276660, C04B 22/00, 2004).

This invention by technical nature and the achieved result is closest to the proposed invention and therefore is taken as a prototype.

Known additive contains the following components, wt.%:

Technical lignosulfonates 3-20 Clay containing montmorillonite 10-40 Refractory clay Rest

The objective of the invention is to find the optimal composition of a multifunctional complex additive, which provides an improvement in the physico-mechanical properties of the resulting concrete.

The problem is solved by creating a comprehensive additive for heavy concrete mixtures, including technical lignosulfonates and clay containing montmorillonite, which additionally contains a deactivated catalyst for the dehydrogenation of cyclohexanol produced by ε-caprolactam and a product of co-dispersion to a particle size of less than 10 ^-2 μm clay containing montmorillonite and ε- caprolactam in a ratio of 1 / 0.5 and castor oil and technical salomas in a ratio of 1/1, with the following ratio of components, mass. %:

Technical lignosulfonates 63-70 Deactivated Dehydrogenation Catalyst cyclohexanol production ε-caprolactam 5-7 Clay containing montmorillonite 16-18 ε-caprolactam 8-9 Castor oil 0.5-1.5 Salomas technical 0.5-1.5

In the process of modifying montmorillonite, reactive ε-caprolactam molecules are adsorbed in the interlayer space and on the surface of montmorillonite particles. As a result of the rupture of the lactam cycle of ε-caprolactam, reactive units are formed that interact with the fatty acids of castor oil and salomas with the formation of esters, oligomers and high molecular weight compounds. Ions of calcium, zinc, copper, a deactivated cyclohexanol dehydrogenation catalyst form fatty acid salts and complex organometallic compounds with high sorption activity, which largely determines the improved surface-active, hardening, plasticizing, colmatizing, inhibitory properties of the additives of the present invention.

The proposed complex additive is made from available substances, including natural and plant origin, as well as waste products of ε-caprolactam production. According to the invention, they are used: technical lignosulfonates TU 5870-002-46849456-03, a NTK series cyclohexanol dehydrogenation catalyst (manufactured by Azot OJSC), clay containing montmorillonite GOST 7032-75 “Bentonite clay for fine and building ceramics”, GOST ε-caprolactam 7850-86, technical salom TU 9145-180-00334534-95, castor oil technical GOST 6757-96.

The components used for the claimed additive are not deficient and do not belong to harmful substances (hazard class IV).

Example 1. A complex additive in an amount of 100 kg is prepared in two stages: first, in a wave vibratory mill, a nanocomposite mixture of 16 kg of montmorillonite and 8 kg of ε-caprolactam (1 / 0.5 ratio), 0.5 kg of castor oil and 0.5 kg of technical salomas (1/1 ratio). After dispersing the mixture, particles smaller than 10 ^-2 microns are sieved.

Then, 70 kg of technical lignosulfonates and 5.0 kg of spent (deactivated) cyclohexanol dehydrogenation catalyst are introduced into the mixture.

Examples 2-4. Prepare a comprehensive additive according to the technology described in example 1.

Example 5. Prepare a comprehensive additive according to the technology described in example 1. After dispersing a mixture in a wave vibratory mill, particles smaller than 10 ^-1 microns are sieved.

Table 1 shows the options for the composition of the examples.

Table 1 No. Name of components The content of components, kg, in samples according to examples one 2 3 four 5 one Technical lignosulfonates 70 63 72.5 58 67

2 Deactivated ε-caprolactam dehydrogenation cyclohexanol catalyst 5 7 four 8 6 3 Clay containing montmorillonite 16 eighteen fourteen twenty 16 four ε-caprolactam 8 9 9 10 8 5 Castor oil 0.5 1,5 0.3 2 1,5 6 Salomas technical 0.5 1,5 0.2 2 1,5

The concrete mixture is prepared by mixing cement of the CVM I 42.5N grade GOST 31108-2003, quartz sand with a fineness modulus (Mkr) 2.0 + 2.5 according to GOST8736-85, crushed stone granite fractions 5.0-20.0 mm according to GOST10268 - 80. The water-cement ratio of the prepared cement mixture (W / C) is 0.30. Concrete mixture corresponding to strength class B22.5 was prepared in accordance with GOST 27006 - 86 and SNiP 82 - 02 - 95 “Federal elementary norms for cement consumption in the manufacture of concrete and reinforced concrete products and structures”. The additive was introduced in an amount of 0.3% by weight of cement in the concrete mixture.

The test results of concrete samples with a complex additive according to examples, with the addition of the prototype and without additives are shown in table 2.

table 2 No. The name of indicators The compositions of the examples one 2 3 four 5 By Without prototype doba wok one The mobility of the mixture according to the draft of the cone, cm, according to GOST 10181-2000 22 23 19 twenty twenty 19 four 2 The start time for setting the mixture, h / min, according to GOST 310.3-76 4/32 4/40 4/22 4/22 4/25 4/22 2/50 3 The termination of the setting of the mixture, h / min 6/10 6/14 5/50 5/45 5/40 5/48 4/10

four Compressive strength, MPa, according to GOST 10180-90 50.8 51.5 45,2 43.8 43.0 41.2 33.5 5 Water absorption,%, according to GOST 12730.0-78 0.015 0.012 0.09 0.1 od 0,094 2.6

As shown in table 2, the complex additive is effective in all variants of the compositions according to the invention (examples 1 to 2). The increase in strength compared with the sample with the addition of the prototype is 23 ÷ 27%. The complex additive proposed by this invention provides mobility of the concrete mixture from P1 to P5, and the additive according to the prototype, respectively, from P1 to P4. The water absorption of concrete samples with the additive of the present invention compared to a concrete sample without additives has decreased by more than 170 times and amounts to 0.012-0.015%.

Deviation from the optimized composition (examples 3-4) or the use of additives of optimized composition, using the product of co-dispersion of clay containing montmorillonite, ε-caprolactam, castor oil and technical salomas with a particle size of more than 10 ^-2 μm (example 5), degrades the physical and mechanical properties of the samples to the level of the prototype.

Using the invention allows to increase the start and end time of hardening of heavy concrete mixtures, increase the compressive strength of concrete, increase the mobility of the concrete mixture and reduce the water absorption of concrete.

Claims (1)

A complex additive for heavy concrete mixtures, including technical lignosulfonates and clay containing montmorillonite, characterized in that it additionally contains a deactivated ε-caprolactam dehydrogenation catalyst for cyclohexanol and a product of co-dispersing to a particle size of less than 10 ^-2 μm clay containing montmorillonite and ε- caprolactam in a ratio of 1 / 0.5 and castor oil and technical salomas in a ratio of 1/1, with the following ratio of components, wt.%:
Technical lignosulfonates 63-70 Deactivated catalyst dehydrogenation of cyclohexanol ε-caprolactam production 5-7 Clay containing montmorillonite 16-18 ε-caprolactam 8-9 Castor oil 0.5-1.5 Salomas technical 0.5-1.5