SU1242482A1 - Concrete mix - Google Patents

Description

The invention relates to the building materials industry, in particular to concrete mixes with chemical additives used during the concrete work in the winter.

The purpose of the invention is to increase the water tightness of concrete while maintaining the mobility of the mixture and the strength of the concrete under operating conditions at temperatures i (-15) - (-17) ° C.

For the preparation of the concrete mixture, from coaluminate Portland cement. M 400, granodiorite crushed stone of a fraction of 10-20 mm, quartz sand with a modulus of 2.18 is used. Chemical additives: ,, FeCl (qualification pure) and sulphite-yeast brew (RRM) - the industrial additive of KBT qualification is introduced into the concrete mixture in the form of aqueous solutions and the workability of the concrete mixture is determined. After determining the workability, the concrete mixture is covered with a damp cloth and stored in the same way. Placement of 1 hour. Then the secondary determination of workability is carried out. Samples of 150 mm and N 150 mm, six pieces per composition, are formed from the newly prepared concrete mixture. After molding the specimens are placed in a refrigerated chamber with temperature -. The swarm (-16) i is 1 ° C and is stored there for 28 days. Conducted a water proof test.

P

Remark-h. P- ; ХЖ - Fe Cl.t КЦ - complex additive.

VNIIPI Order 3664/24

Random polygons , Uzhgorod, st. Project, 4

The compositions of the concrete and the test results are given in the table.

Increasing the dosage of the NRM is necessary to suppress the effect of accelerating the hardening of concrete when using potassium carbonate, which causes a rapid loss of mobility of the mixture. The adsorption of MDB molecules on the granules reduces the hydraulic activity of the cement, inhibits the process of its hydration, increases. It preserves workability over time.

Additional supplementation

FeClj provides for the formation of cement in the process of solidification of amorphous hydration products deposited in the pores of the concrete, thereby reducing its permeability. The specified dosage of the components of the concrete mix ensures the production of a cast concrete mix with a draft of 14-16 cm, which is necessary for the pneumatic transport of the concrete mix and concreting.

reinforced reinforced concrete constructions.

Control concrete mixes without additives harden the negative temperature.

thirty

I

The control concrete mixtures have mobility under normal conditions after preparation of 14 cm and after 1 h 10 cm, the compressive strength is 36.4-37.0 MPa.

Circulation 640

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Claims (1)

CONCRETE MIX, including Portland cement, sand, gravel, potassium carbonate, sulphite-yeast mash and water, characterized in that, in order to increase the water-tightness of concrete while maintaining the mobility of the mixture and the strength of concrete in operating conditions at a temperature of (-15) - (-17) ° C, it additionally contains ferric chloride in the following ents, wt. X: Portland cement Sand Crushed stone Potassium carbonate Sulphite yeast mash Chloric iron Water compo 20-21 19-21 47-49 1,815-2,032 0.193-0.23 0.175-0.297 Else Q sc SU „„ 1242482 1,121