SU833715A1 - Concrete mix - Google Patents

Description

(54) CONCRETE MIXTURE

The invention relates to building materials, namely to concrete mixtures containing slit additives. Known concrete mix for hydraulic structures, including saponified wood pitch as a surface-active additive TsNIIPS-1 1. This mixture has insufficient workability. On its basis, concretes with relatively low strength characteristics are obtained. Closest to the proposed concrete mix, including cement, sand, coarse aggregate, water and an additive based on products of wood chemical production. As a product of wood chemical production, a phenolic wood chemical reducer is used in the amount of 0.006-0.06% of the total mass 2. A known concrete mixture, which also has relatively low workability and does not have the ability to preserve it for a long time. The purpose of the invention is to improve the workability of the concrete mix. This goal is achieved by the fact that the concrete mixture, including cement, sand. coarse aggregate, water, and an additive based on wood-chemical production contains, as an additive, a neutralization product with a displaced calcium and soda-calcium base of wood dry-distilled pyrocondensates in the following ratio, wt.%: Cement 11.6-14.8 Sand31.6-34.6 Coarse aggregate47 , 5-49.2 Additive0.006-0.06 WaterOther Proposed additive by chemical composition is a mixture of various phenols and alkylphenols in the form of Ca and Na phenols (25-30%); Ca and Na salts of phenolic acids, Ca and Na salts of hydroxy acids (5-8%); Ca and Na salts of carboxylic acids (5-7%); levoglucosan (30-35%). The additive is introduced into the concrete mix with mixing water, in which it is easily dissolved. The presence of Ca and Na salts of hydroxy acids, phenolic acids and carboxylic acids contributes to air entrapment, which creates an additional effect of plasticization.

The ability to preserve the workability of the concrete mix for a long time is achieved by chemical interaction of alcohol, acid, and phenolic functional groups with calcium oxide released from clinker minerals.

As a result, a protective layer of the surfactant is formed around the grains of cement, which inhibits its hydration in the early period.

Cement

Sand

Coarse aggregate

(rubble)

Additive - a product of neutralization with mixed calcium and soda-calcium base wood dry pyrocondensates

Phenonic fox

chemical (water)

Properties

Value, cm

The tensile strength of MP szh..1n, ia through

23 ut

The presence of levoglucosane in the composition of the additive contributes to the lengthening of the setting time.

In tab. 1 shows the proposed and known compositions of the mixtures.

In tab. 2 shows the properties of the proposed and known compounds,

Thus, the proposed concrete mix is more mobile than the known one, which allows reducing the consumption of cement without loss of strength.

Table 1

14,812,012,0

31.634,634,6

47,747,547,5

0, O10,060,06

5,895,845,84

table 2

Composition

proposed

famous

9

23,524.5 25,521,5

31,532.0 34.029.0

Claims (2)

1. Recommendations for the use of chemical additives in concrete. M., stroiizdat, 1977, p. 2 and 13. 2. USSR author's certificate number 709586, cl. From 04 To 13/24, 08.16.76.