RU2358938C1 - Fine-grained concrete - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: fine-grained concrete contains Portland cement, glauconite sand and water. Filler used is crushed glauconite sand with specific surface of S_sp=350 m²/kg. Additive used is superplasticiser C-3 at the following ratio of components, wt %: Portland cement 18.0-19.0; Glauconite sand 68.1-68.9; Filler 1.0-2.0; Superplasticiser C-3 0.1-0.2; Water 11.0-11.7.

EFFECT: increased strength during compression and bending and reduced water absorption and shrinkage of fine-grained concrete from raw mix.

2 cl, 2 tbl

Description

The invention relates to building materials and can be used for the manufacture of products from fine concrete, both in civil and in industrial construction.

Known raw mix for the manufacture of fine-grained concrete containing cement, sand and water (Bazhenov Yu.M. Concrete technology. - M.: Publishing house ASV, 2002. - p.274-275).

Fine-grained concrete based on this raw material mixture has a reduced compressive and bending strength and increased porosity.

A known raw material mixture for the manufacture of fine concrete, including Portland cement 19.00-20.00, sand 58.80-61.92, water, aluminum powder 0.024-0.025, surfactant SDB 0.009-0.01, sodium sulfate 0, 24-0.25, spent catalyst for isoprene production 1.56-4.68 and water (patent 2198861).

The disadvantages of this mixture for fine-grained concrete are: low compressive strength, low density, a large number of components (7 pieces) that reduce the uniformity of the mixture, as well as the complexity of its manufacture.

Closest to the technical nature of the claimed invention is a raw mixture containing wt.%: Cement 0.3, treated with a 0.03% solution of hydrochloric acid, glauconite sand 67 and water (patent 2275344).

The disadvantage of this technical solution is the reduced compressive strength.

The objective of the invention is to obtain a raw material mixture for the manufacture of fine concrete, with increased compressive strength, bending and low water absorption.

The solution to the problem is achieved by the fact that the raw mixture contains Portland cement, glauconite sand and water. As a filler, ground glauconite sand with a specific surface area S _beats = 350 m ² / kg is used, and S-3 superplasticizer is used as an additive in the following ratio of components, wt.%:

Portland cement 18.0-19.0

Glauconite sand 68.1-68.9

Filler 1.0-2.0

Superplasticizer S-3 0.1-0.2

Water 11.0-11.7

Glauconite sand contains 87% SiO ₂ .

The filler in the form of ground to a specific surface S = 350 m ² / kg glauconite sand has a dual function. On the one hand, it helps to reduce the voidness of the aggregate, which is mainly represented by particles with a size of 0.315 and less than 0.16 mm (the void volume is 0.44%), and on the other hand, it leads to the formation of an increased amount of low-basic hydrosilicates of the CSH (I) type.

Thus, the formation of a dense skeleton, an increase in the plasticizing effect, and, as a consequence, a decrease in mixing water, an increase in the hydration activity of the components of the raw material mixture, made it possible to obtain fine-grained concrete, characterized by increased compressive strength, bending, and reduced water absorption.

The claimed combination of essential features exhibits a new property, which provides an increase in the hydration activity of the components of the raw material mixture with a reduced W / C ratio and the formation of a structure with a tight package.

The combined presence of ground glauconite sand in combination with the C-3 superplasticizer provides the total effect, which is manifested in increased compaction and hardening of the structure of the resulting artificial stone, which results in an increase in strength at design age by compression by 87%, bending by 70% and a decrease water absorption by 45%.

The claimed invention is industrially applicable and can be used in industrial and civil engineering.

Prepare the raw mix as follows.

1. Dose Portland cement, sand and filler, presented ground glauconite sand with S _beats. = 350 m ² / kg.

2. Dose water.

3. Dose C-3 superplasticizer and add to the prepared water.

5. Dosed components of the raw mix are placed in a concrete mixer, in which thorough mixing of all components is carried out. The result is a raw mixture from which the required products and samples are made for quality control according to the studied parameters. Hardening of concrete was carried out in a steaming chamber according to the regime of 3 + 5 + 4 hours. The test results are presented in tables 1, 2.

From table 2 it is seen that with this method, a technical result is achieved. The proposed raw mix according to this invention provides for obtaining fine-grained concrete, which differs from the prototype in increased compressive strength by 73%, bending by 70% and a decrease in water absorption by 45%.

Table 1 Example The composition of concrete, wt. % Portland cement glauconite sand filler (ground glauconite sand with S = 350 m ² / kg) S-3 Water Prototype 27.17 55.17 - - 17.66 Proposed
one 27.11 55,42 - - 17.47 2 17.0 67.6 3.0 0.3 12.1 3 18.0 68.1 2.0 0.2 11.7 four 19.0 68.9 1,0 0.1 11.0

table 2 Indicators Compositions prototype one 2 3 four The limit of compressive strength, MPa 10.9 10.1 13.8 18.9 18.5 Bending Strength, MPa - 2,4 3.3 4.1 4.0 Water absorption,% - 5.3 3,5 2.9 3,1

Claims (2)

1. Fine-grained concrete containing Portland cement, glauconite sand and water, characterized in that as a filler used ground glauconite sand with a specific surface area S _beats = 350 m ² / kg, and as an additive - superplasticizer S-3 in the following ratio of components, wt.%:
Portland cement 18.0-19.0 Glauconite sand 68.1-68.9 Filler 1.0-2.0 Superplasticizer S-3 0.1-0.2 Water 11.0-11.7 2. Fine-grained concrete according to claim 1, characterized in that glauconite sand contains 87% SiO ₂ .