RU2222507C2 - Complex additive "alvik" - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: additive with additionally included amines, more specifically urea or triethanolamine, contains, wt %: chloride salt (hardening accelerator) 14-30, sodium or calcium formate (plasticizer) 6-10, amines 7- 14, and water - the balance. EFFECT: increased strength upon hardening of concretes under natural conditions and when using thermomoist treatment. 3 cl, 2 tbl

Description

The invention relates to the construction and construction materials industry using heavy and lightweight concrete and mortars, including cellular ones.

It is known to use additives of aqueous solutions of electrolytes: calcium chloride, calcium oxalates, aluminum hydroxide, and others in compositions based on binders (Japanese application No. 56-37256, class C 04 V 7/35, C 04 V 13/00).

The disadvantage of this invention is the decrease in strength in the later stages of hardening and its low efficiency when steaming products.

The closest in technical essence and the achieved result to the claimed invention is an additive consisting of hardening accelerators: salts of hydrochloric acid and plasticizer formate (RU No. 2168478, publ. 10.06.2001).

The disadvantage of this additive is its low efficiency during heat-moisture treatment of the product and the insufficient intensity of hardening in the later stages of hardening.

The objective of the present invention is to increase the strength of steamed products and increase the intensity of hardening in the later stages.

 In a complex additive that includes a hardening accelerator — hydrochloric acid salt, plasticizer formate and water, the accelerator additionally contains amines, in the following ratio, wt.%:

Salt of hydrochloric acid 14 - 30

Formate 6-10

Amines 7-14

Water Else

The complex additive as amines may contain urea and triethanolamine The complex additive as formate may contain sodium or calcium formate.

At relatively small amounts compared to chlorides, amines accelerate the hardening process and increase strength at a later date due to exchange reactions with hydrated compounds of cement systems.

Formates not only plasticize concrete and mortar mixtures, but in combination with other components contribute to the growth of strength, especially after heat and moisture treatment.

An example of a specific implementation. 428 g of Portland cement grade 500, 104.44 g of quartz sand, 167 ml of water, 2.56 g of a complex additive and 900 ml of foam were mixed (composition 3, table 1). The foam was made on the basis of secondary sodium alkyl sulfates. The amount of additive, which includes 0.86 g of calcium chloride, 0.52 g of sodium chloride, 0.3 to 8 g of urea, 0.28 g of triethanolamine, 0.52 g of sodium formate and 3.84 ml of water, corresponded to the content of hydrochloric salts in the additive acids - 21.6%, amines - 10.3%, formates - 8.1%, water - 60%. For testing, samples were made cubes 10x10x10 cm from a foam concrete mixture of the specified composition. Similarly, samples were prepared with various amounts of complex additives. For comparison, samples with a known additive were made (Table 1).

In table 1:

in example 2, the amount of additive by weight of the concrete mixture is 0.35 wt.%;

in example 3 - 0.83 wt.%;

in example 4 - 1.32 wt.%;

in example 5, 0.16 wt.%;

in example 6, 1.52 wt.%;

in example 7 - 1.32 wt.%;

Some of the samples hardened in humid conditions, the other was subjected to heat-moisture treatment in a laboratory steaming chamber at an isothermal exposure temperature of 95 ° C. Then the samples were unformed and tested on the press to determine the ultimate compressive strength. The results of determining the strength indicators are given in table. 2.

The data table. 2 allow us to conclude that the samples with the claimed additive have a higher strength compared to the standard, both during natural hardening and after heat and moisture treatment.

Similar results were obtained when testing additives in samples of heavy concrete.

The additive can be used in monolithic concrete.

The advantage of the proposed additives is its use in liquid form, which facilitates dosing and provides good mixing.

Claims (3)

1. A complex additive comprising a hardening accelerator — hydrochloric acid salt, a plasticizer — formate and water, characterized in that the accelerator additionally contains amines in the following ratio of components, wt.%: Salt of hydrochloric acid 14 - 30 Formate 6-10 Amines 7-14 Water Else 2. The complex additive according to claim 1, characterized in that it contains urea and triethanolamine as amines. 3. The complex additive according to claim 1, characterized in that as formate, it contains sodium or calcium formate.