SU1070126A1 - Concrete mix - Google Patents

Abstract

CONCRETE MIXTURE, which includes cement, crushed stone, sand, plasticizing agent based on polyacrylonitrile and water, is absent because, in order to increase the tensile strength during bending and cold resistance of concrete while maintaining the workability of the mixture, it contains, as a plasticizer, a water-soluble waste from the production of nitron fiber of the general formula (-CHJ-CH-CI-CI-CH | - CH-) n - (- CHj-C) „- (-CHjC4HN | CBCCBVtoONfl -№ -) ... {- CHi-CH-CH, -Cp) "coonaCO c-0 n where r 240, with the following ratio of components, May.%: Cement 16-21 Crushed stone 49-58 Sand 16-25 i Water soluble. production waste (Nitron fiber follicles 0.2-0.56

Description

to

o :) The invention relates to building materials, namely concrete mixes containing modified additives. A known concrete mixture with an added plasticizer based on water-soluble sylphated copolymers of (meth) acrylic acid and their derivatives Clj. Closest to the proposed technical essence and achievable result is a builder for a mixture based on cement, containing aggregate, water and the addition of hydrolyzed polyacrylonitrile in the amount of 1-5% by weight of cement C2J. A disadvantage of the known concrete mixes is the relatively low flexural tensile strength and frost resistance of concrete. The purpose of the invention is to improve the flexural tensile strength and frost resistance of concrete while maintaining workability. This goal is achieved by the fact that a concrete mixture, including cement, crushed stone, sand, a plasticizing agent based on polyacrylonitrile and water, contains as a plasticizing agent a water-borne waste from the production of nitronic fiber of general formula 1-cn - Сн, - (-) „- (- с г- с)« - (-нн, COlMi СБОКвсакCOOWa -СН-) -... (- СНг-СН-СН, -С) „

The table where p is 240 with the following ratio of components, wt.%: Cement 16-21 Crushed stone 49-58 Sand 16-25 Water-soluble waste production of nitrone fiber 0.2-0.56 Water Other The water-soluble waste production of nitronic fiber - polyelectrolyte K-9 is an acrylic copolymer 92.7% acrylonitrile, 6% methyl methacrylate, and 1.3% itonoic acid. The mechanism of action of a water-soluble polymer additive is that the additive cures without a hardener in the alkaline environment of the cement stone, and going into a waterproof state forms a networked transitive structure of the polymer chains penetrating the cement stone. The method of preparing a concrete mix consists in mixing all its components with the mixing water, into which the proposed water-soluble additive is previously introduced. Table 1 presents the compositions of concrete mixes; in table 2 - their properties ..

Cement Crushed Sand

Water soluble waste production of nitron fiber

Hydrolyzed polyacrylate nitrile

Water

21 16.0 18.5 21 18.5 49 58 53.5 49 53.5 25 15.64 19.59 2l, 6 17.5

-

1.05 0, 16 0.46 10.20 7.95 7.35 10.5

Workability,

cm

Strength at compression, MPa at age:

7 days

28 days

Strength at

bending stretch

MPa, at the age of 28 sous

Brand on frost resistance Brand on water tightness

Supplement cost

rub / m concrete

From the test results we can see that the proposed mixture has advantages over the prototype both in terms of strength characteristics and durability; A particularly significant advantage of the composition with the addition of a water-soluble polymer on the basis of the NVG over the prototype (with the addition of hydrolyzed polyacrylonitrile) in compressive strength in the early stages, as well as in tensile strength during bending.

For example, composition 2, compared with the analogous composition of the prototype (composition 4), has a 29% greater compressive strength and 15% greater tensile strength during bending (28 days old).

In terms of the tensile strength during bending, the advantage of composition 2 (with the addition of GCC) over the similar composition without additive (composition 7, control) is even greater (36%). The latter indicates that it is most expedient to use the proposed concrete mix for thin-walled structures subjected to tensile stresses, for example, for airfield slabs and road surfaces.

table 2

5.0

5.0 5.0

50.8 27.7 28.6 26.1 35.0 / 100 63.5 44.3 48.9 57.7 45.1 / 100

8.5 4.8 6.1 8.0 5.3 / 100

800 300

400

500 200

18

18

18

20

21-, 5 13.5, 6 88.2

The brand of frost resistance and water resistance of concrete with the addition of CIA n-a and 2-3 brands are higher compared with the corresponding compositions of the prototype and significantly more than the brand of frost resistance of the control composition without additives.

The advantage in frost resistance will be even greater when using non-frost resistant compounds: for example, if the frost resistance mark of the control compound without an additive (in table 2 and not used) is 50, then the frost resistance grade of the same composition with 2% of the ADH additive is 500, i.e. . 10 times more.

The water resistance of the proposed mixture is 1 brand higher than the prototype and several brands are control coz; tav. .

Increased extensibility and lesser shrinkage of the composition with the addition of CBS make it possible to prevent shrinkage destructive processes when concrete hardens in an environment with low humidity and elevated temperature.

The compositions of the used concrete mixes made with the same W / C and the results of their tests are averaged in Table 3.

Table 3

Claims (1)

CONCRETE MIXTURE, including cement, crushed stone, sand, a plasticizing agent based on polyacrylonitrile and water, characterized in that, in order to increase the tensile strength during bending and frost resistance of concrete while maintaining workability of the mixture, it contains a water-soluble waste of intron production as a plasticizing additive fibers of the general formula (JOOHa (-CH.-CH-CH, - sn- ··· - sn, - sn-) _p - (- sn _g C) _p - (- CH, - SOKHI, SOCHYA Sim SOOTI -CH-) _I - ... (- CH _a -CH-CH1-Cp) _p sohoja with "oh sooo X where h = 240, with the following ratio of components, May.%: Cement 16-21 Crushed stone 49-58 Sand 16-25 FROM Water Soluble Nitron Production Waste in cells fiber 0.2-0.56 F Water Rest Chi