SU1691349A1 - Method for obtaining concrete mix - Google Patents

Abstract

The invention relates to building materials and can be used in the production of concrete mixes and concrete with chemical additives. The purpose of the invention is to increase the strength of concrete and reduce its shrinkage, increase the workability of the concrete mix. The composition of the concrete mix, wt.%: Sandstone cement 17.6-20.0, aggregates with a specific surface of not more than 16 cm / g fraction 10.00-20 , 00 mm 21.8- 23.5; fractions 2.5-5 21.8-23.5, fractions 0.63-1.25 mm 21.8-23.5; alkyl resorcinol epoxy resin 4.5-6.0; poly (ethylene polyamine) 0.39-058, 1-heptanol 0.01-0.02; water 7.0-8.0. Aggregates are mixed with alkylresorcin epoxy resin and polyethylene polyamine until they are uniform and then, without stopping the mixing, water, portland cement, and 1-heptanol are introduced. The mobility of the concrete mix is 9.0-10.6 cm, the shrinkage of concrete is 0.22-0.24 mm / m, the strength of concrete is 42.0-45.3 MPa. 2 tab. (Ls

Description

The invention relates to building materials and can be used in the production of concrete mixes and concrete with chemical additives.

The purpose of the invention is to increase the strength of concrete and reduce its shrinkage, increase the workability of the concrete mix.

Portland cement 400 is used to prepare concrete mixes; aggregates of granite fractions are 10.0-20.0 mm; 2.5-5.0 mm; 0.63-1.25 mm; tap water drinking. The epoxy resin alkylresorcinov meets the requirements of Spec. 38.1091-76 and is a viscous homogeneous liquid of dark brown color and contains, in wt%:

Epoxy groups, not less than 20

Chlorine ion, not more than 0.016

Total chlorine, not more than 1.5

Volatile matter, not more than 2.0.

Dynamic viscosity at 25 ° С - 1.180 1.190 g / cm3.

1-Heptanol (heptyl alcohol) CH 3 (CH 2) 5 CH 20 H, M 116.21, is a colorless liquid with a density of 0.82 g / cm 3.

Polyethylene polyamine is a dark red liquid with an ammonia smell that smokes in air.

The prototype polyvinyl acetate-epoxy dispersion is obtained by combining 100 wt.h. polyvinyl acetate dispersion of PVA brand D50S and aqueous dispersion of a copolymer of vinyl acetate with ethylene of the SVED brand SVZD10V with 30 wt.h. epoxy resin.

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The concrete mixture of the prototype and the control composition is prepared by mixing the components in a concrete mixer for 2 minutes until a homogeneous state (examples 4.5).

The concrete mixture according to the invention is prepared according to the following technology: the mixture of three aggregate fractions, polyethylene polyamine alkyl resorcinol epoxy resin is mixed until uniform, then, without interrupting, water, portland cement and 1-heptanol (examples 1-3) are introduced into 1-2 minutes

The workability of the concrete mixture is determined by the draft of the standard cone, the strength and shrinkage of the concrete are determined on prisms 7 x 7 x 28 cm after 28 days of normal hardening.

The compositions of concrete mixes and concrete are given in table. 1, the test results of their properties are given in table. 2

As follows from the test results, the use of concrete mix of the proposed composition (examples 1-3) allows to increase the strength of concrete and reduce its shrinkage, to improve the workability of the concrete mix.

Claims (1)

The invention The method of preparing a concrete mix, comprising mixing Portland cement, aggregate fraction 10-20 mm, 2.5-5 mm, 0.63-1.25 mm of epoxy, polyethylene namine and water, characterized in that, in order to increase the strength of concrete and reduce its shrinkage, improve the workability of the concrete mix, the aggregate with a specific surface no more. 16 cm2 / g of these fractions are mixed with alkali resorcinol epoxy resin and polyethylene polyamine to obtain a homogeneous mixture, into which, without interrupting mixing, water, portland cement and additionally 1-heptanol are added in the following ratio of components, wt.%: Portlandcement17.6-20.0 Aggregates fr. 10-20 mm 21.8-23.5 fr 2.5-5 mm21.8-23.5 fr 0.63-1.25 mm21.8-23.5 Al Kilresorcinov epoxy resin4.5-6.0 Polyethylenepolyamine 0.39-0.58 1-Heptanol 0.01-0.02 Water Rest Polyvinyl acetate noepoxidine dispersed. The surface area of the aggregates is in the specific surface of the aggregates was set to pyramide, 1-1 h, 6 2-11) .9 cm1 / g; 3 - 16.0 b - 16.5 oG / P 5 - 15.0 6 - 16.5 cm1 / g; 7 - 13.0 cm1 / g.