SU1184834A1 - Complex additive for concrete mixture - Google Patents

Description

The invention relates to the production of building products, namely, the composition of complex additives for the • concrete mix.

The purpose of the invention is to increase the strength and water resistance of concrete while maintaining the plasticity of the concrete mix.

A concrete mix was prepared on the basis of Portland cement M-500 of the following composition: cement: sand: crushed stone = = 1: 1.53: 2.6 with W / C = 0.35. The following aggregates were used in the work: crushed granite fraction 5–20 mm, ravine sand with Mr _K- = 2.35.

The compressive strength of concrete was determined according to GOST 10180-74, the mobility of the concrete mix according to GOST 10181 is 62; water tightness in accordance with GOST 12730,5-78. The aldol condensation of formaldehyde (temperature 60 ^e C, mass ratio of formaldehyde / calcium hydroxide / - 10, reaction time 3 h) and hardening accelerators were used as a complex additive. As the latter, the following compounds were used: sodium chloride, aluminum sulfate, sodium nitrate, sodium carbonate, sodium hydrogen phosphate, calcium metaphosphate, sodium nitrite, sodium nitrate, calcium formate, urea. The proposed complex additive was introduced into the concrete mix in the amount of 6 ^ от by the mass of cement.

Example 1. A concrete mix of the indicated composition was prepared without complex additives.

Examples 2-4. A complex additive was introduced into the concrete mixture of the indicated composition with a ratio of components to the aldol condensation product of formaldehyde: sodium chloride, equal to 12.5: 87.5;

31: 69; 50: 50, respectively.

Examples 5-7. In concrete

a mixture of this composition was administered I

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complex additive, as in examples 2-4, but as the accelerator used aluminum sulfate.

Examples 8-10. In concrete 5 mixture of the composition injected

complex additive, as in examples 2-4, but as the accelerator used sodium nitrate.

Examples 11-13. In the concrete ’θ mixture of the composition injected

complex additive, as in examples 2-4, but as the accelerator used sodium carbonate.

Examples 14-16. In the concrete mixture 15 of the composition was injected

complex additive, as in examples 2-4, but as the accelerator used sodium hydrogen phosphate.

Examples 17-19. In the concrete mix 20 of the composition injected

complex additive, as in examples 2-4, but as an accelerator used calcium metaphosphate.

Examples 20-22. 25 concrete mixture of the composition was injected

complex additive, as in examples 2-4, but as the accelerator used nitrite-nitrate, sodium.

Examples 23-25. In the concrete 30 mixture of the composition injected

complex additive, as in examples 2-4, but as the accelerator used calcium formate.

Examples 26-28. In the concrete 35 mixture of the composition injected

complex additive, as in examples 2-4, but urea was used as an accelerator.

40 The results of testing a concrete mix in the presence of the proposed additive are presented in Table. one.

BUT

The compositions and results of tests of the known complex additive of the prototype are presented in Table 2.

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Table 1

Example Mobility of the concrete mix, OK, eat The strength of concrete in compression and the age of 28 days "KPA Water resistant

one 3.0 38.0 AT 4 2 21 52.1 AT 12 3 22 53.5 .. AT 12 four 21 54.0 AT 12 five 21 50.1 AT 12 6 22 " 50.8 ' B-14 7 22 52.0 B-14 eight 22 52.6 AT 12 . 9 ²³ 53.1 AT 12 ^ten 21 50.6 B-14 ,one 20 51.0 B-14 12 22 53.2 B-14 13 • 21 51.6 B-14 14 20 49.5 AT 12 15 21 51.0 B-14 sixteen 21 . 50.3 AT 12 17 22 53.3 B-14 18 21 52.6 AT 12 nineteen 21 51.0 AT 12 20 23 53.6 B-14 21 22 543 B-14 22 22 53.0 B-14 23 20 51.6 B-14 24 22 50.1 AT 12 25 21 53.0 AT 12 26 23 49.5. AT 12 27 21 51.6 AT 12 28 21 52.0 AT 12

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table 2

————————— η Accelerator Type Components of the known additive (by weight of cement), May L * The mobility of the concrete mix, OK, cm Strength at compression at the age of 28 days, MPa Water resistant Plasticizing additive** Accelerator

Nitrite-nitrate calcium chloride (prototype) _2 20.0 _Ы_ 80.0 20 . 44.0 AT 8 _Ъ0_ _'And _z o_ 23 46.0 AT 10 Also 50.0 50.0 - ⁿ - _4 _X 8_ 80.0 _1d2_ 20.0 21 45.5 AT 8

* in the numerator, the amount of the additive by weight of cement (May L), in the denominator, the ratio of the components of the complex additive (MayL);

** plasticizing additive prototype - a mixture of sulfonated

melamine condensation products with formaldehyde at a ratio of 1: 1.

Claims (1)

COMPLEX ADDITIVE FOR CONCRETE MIXTURE, including plasticizer - a formaldehyde-based condensation product and an accelerator hardening, characterized in that, in order to increase the strength and impermeability of concrete while maintaining the mobility of the concrete mix, it contains as a plasticizer the product of aldol condensation of formaldehyde in the presence of an alkali or alkaline earth hydroxide, and as a hardening accelerator a substance from the group: sodium chloride, sulfate aluminum, sodium nitrate, sodium carbonate, sodium hydrogen phosphate, calcium metaphosphate, sodium sodium nitrate, calcium formate, urea in the following ratio of components, ma.X: The specified plasticizer 12,5-50,0 The specified hardening accelerator 50,0-87,5 5TS 1184834 > 1 11