RU2425814C1 - High-strength concrete - Google Patents

Abstract

FIELD: construction. ^ SUBSTANCE: high-strength concrete is made of a mixture of raw materials, which contains a complex additive from ferric hydroxide sol (III) with density of 1.021 g/cm3, hydrogen index 4.5-5.5 and a hyperplasticiser Peramin SMF-10, at their following ratio, accordingly, in wt %: 85.50-86.00 and 14.00-14.50 and the following ratio of raw materials mixture components, wt %: portland cement 20.60-27.40, sand 21.80-24.70, crushed stone 42.40-44.50, the specified additive 1.00-1.45, water 7.40-8.75. ^ EFFECT: increased compression strength of concrete. ^ 3 dwg, 1 tbl

Description

The invention relates to building materials and can be used for the manufacture of concrete products in civil and industrial engineering, as well as in the construction of structures for special purposes.

A known raw material mixture for the manufacture of high-strength concrete (Yu.M. Bazhenov. Concrete technology. Publishing House of the Association of Building Universities (DIA), Moscow, 2002, p. 377), containing Portland cement, silica-containing component, sand, gravel, silicate flour, additive and water.

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

Known raw mix for the manufacture of high-strength concrete (RU No. 2256629, С04В 28/04, publ.: July 20, 2005), containing: Portland cement, sand, gravel, silica-containing component, represented by orthosilicic acid sol with a density of 1.014 g / cm ³ , a hydrogen indicator of 5-6, the addition of "Deya-M" and water.

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

The closest in technical essence to the claimed invention is high-strength concrete (RU No. 2323910, С04В 28/04, 22/06, 111/20, publ.: 05/10/2008), containing: Portland cement, sand, gravel, additive - sol iron (III) hydroxides with a density of 1.018 g / cm ³ , a hydrogen index of 4.5-5.5 and water in the following ratio of components, wt.%:

Portland cement 23.6-26.9 Sand 23.7-25.2 Crushed stone 36.8-38.4 Sol of iron (III) hydroxide with a density of 1.018 g / cm ³ , pH 4.5-5.5 0.7-0.76 Water 11.9-12.04

The disadvantage of this technical solution is the limited attainable value of compressive strength.

The problem to which the invention is directed, is the creation of high-strength concrete with increased compressive strength.

The technical result is achieved by the fact that in high-strength concrete, obtained from a mixture containing Portland cement, sand, gravel, additive and water, the additive is complex and consists of iron hydroxide sol (III) with a density of 1.021 g / cm ³ , a hydrogen index of 4.5 -5.5 and Peramin SMF-10 hyperplasticizer in the following ratio of components, wt.%:

Sol of iron hydroxide (III) with a density of 1.021 g / cm ³ , pH 4.5-5.5 85.50-86.00 Hyperplasticizer "Peramin" SMF-10 " 14.00-14.50

in the following ratio of components of the raw mix, wt.%:

Portland cement 20.60-27.40 Sand 21.80-24.70 Crushed stone 42.40-44.50 Specified Additive 1.00-1.45 Water 7.40-8.75

The sol of iron (III) hydroxide has a colloidal particle with a positive charge, which helps to enhance hydration processes, and in combination with the Peramin SMF-10 hyperplasticizer gives an ultra-total effect, which allows to obtain high-strength concrete of improved quality.

The problem of creating high-strength concrete is currently relevant, since all areas of construction are developing especially rapidly. One of the ways to create high-strength concrete is the chemical activation of the concrete mixture.

Analysis of the data obtained in the table shows that the proposed complex additive has a plasticizing effect on the cement-containing system, reducing the amount of mixing water by 10%, while the water-cement ratio decreases from 0.47 to 0.32, which contributes to the formation of a denser structure.

The result of the use of this complex additive is an increase in compressive strength of concrete by 41% to a value of 78.1 MPa.

Despite the increased activating effect of the considered additive based on a sol of iron hydroxide (III), the achieved plasticizing effect is insufficient. This limits the scope of the prototype in the construction work. Therefore, to increase the specified plasticizing effect, the joint action of the iron (III) hydroxide sol with the well-known highly effective Peramin SMF-10 hyperplasticizer was considered.

Figure 1 shows the x-ray control (non-additive) composition of high-strength concrete.

Figure 2 shows the x-ray of the prototype.

Figure 3 shows the x-ray composition of the developed concrete.

On the radiographs shown in Figures 1, 2 and 3, are conventionally marked: ■ - calcium hydroxide; ● - alit; ▲ - tobermorite-like hydrosilicates.

The physical and chemical studies using the x-ray phase analysis method showed that in the presence of a complex additive represented by iron (III) hydroxide sol in combination with Peramin SMF-10 hyperplasticizer (Figure 3), the hydration activity of cement in the resulting concrete is increased compared to with control additional concrete (Figure 1), which can be judged by a significant decrease in lines at an interplanar distance equal to (2.77; 2.73; 2.63; 1.76) × 10 ^-10 m, characteristic of alite ( ●).

Moreover, it should be noted that in the presence of a complex additive, the peak intensity increases at an interplanar distance equal to (4.93; 2.60; 1.93) × 10 ^-10 m, characteristic of the formation of calcium hydroxide (■), and the peak intensity also increases with an interplanar distance equal to (2.85; 2.83; 2.42; 2.01) × 10 ^-10 m, characteristic for the formation of tobermorite-like hydrosilicates (▲), compared with the x-ray of a cement stone activated with an iron hydroxide sol (III ) (Figure 2).

Thus, the comprehensive physicomechanical and physicochemical studies have shown that the combination of iron (III) hydroxide sol additive and Peramin SMF-10 hyperplasticizer is favorable, as it enhances the plasticizing effect of the complex additive as a whole. The complex additive in the combination presented has a high plasticizing and activating effect on the cement-containing hardening system, thereby increasing the durability of the artificial stone.

At the filing date, according to the applicant, the claimed high-strength concrete is not known and this technical solution has a world novelty.

The claimed combination of essential features exhibits a new property in the presence of an iron (III) hydroxide sol with a density of 1.021 g / cm ³ and a hydrogen index of 4.5-5.5 and Peramin SMF-10 hyperplasticizer, namely, it increases the mobility of the concrete mix, and also increases the hydration activity of cement, the result of which is an increase in compressive strength of concrete in comparison with the prototype.

The mixture, including Portland cement, sand and crushed stone and the proposed complex additive, provided high-strength concrete, characterized by increased compressive strength. The proposed high-strength concrete according to this invention increases the strength at the design age (28 days) under compression by 24% to a value of 88.1 MPa compared to the prototype.

According to the applicant, the claimed invention meets the eligibility criterion - inventive step.

The claimed invention is industrially applicable and can be used in civil and industrial engineering, as well as in the construction of structures for special purposes.

Prepare the raw mix as follows.

Sol of iron (III) hydroxide: 3-4 drops of a saturated solution of iron chloride are added to 100 cm ^{3 of} boiling water. In this case, hydrolysis of iron chloride proceeds vigorously and the appearing molecules of iron (III) hydroxide condense into colloidal particles. The resulting iron (III) hydroxide sol has a cherry-brown color.

Thus, a sol of iron hydroxide (III) is obtained with a density of 1.021 g / cm ³ , a hydrogen index of 4.5-5.5, which is a cherry-brown liquid.

Dosage sol and Peramin SMF-10 hyperplasticizer based on polycarboxylic polymers of the Swedish company Perstorp (ASTM C494 type F, DIN 1045, BS 5075 parts 1 and 3, EN 934-2) (hereinafter referred to as Peramin SMF-10 hyperplasticizer) ) are placed in dosed water. Dispensed components of the raw material mixture: Portland cement M400, sand with a particle size modulus of 2.1, crushed stone fractions of 5-10 mm and water containing a dosed complex additive are placed in a concrete mixer, where the components are mixed and the concrete mixture is prepared from which the required concrete products are made and samples for quality control in terms of compressive strength.

Concrete hardening was carried out under normal conditions and the test results, according to GOST 10180-90 “Methods for determining the strength of control samples”, are presented in the table.

Analysis of the data presented in the table shows that the proposed high-strength concrete according to this invention increases the strength at design age (28 days) under compression by 24% to a value of 88.1 MPa compared to the prototype.

Claims (1)

High-strength concrete obtained from a raw material mixture containing Portland cement, sand, gravel, additive and water, characterized in that the additive is complex and consists of iron hydroxide sol (III) with a density of 1.021 g / cm ³ and a hydrogen index of 4.5-5 , 5 and Peramin SMF-10 hyperplasticizer in the following ratio of components, wt.%:
The iron hydroxide sol (III) with a density of 1.021 g / cm ³ and pH 4.5-5.5 85.50-86.00 Hyperplasticizer "Peramin SMF-10" 14.00-14.50
in the following ratio of components of the raw mix, wt.%:
Portland cement 20.60-27.40 Sand 21.80-24.70 Crushed stone 42.40-44.50 Specified Additive 1.00-1.45 Water 7.40-8.75

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