RU2226517C2 - Method of manufacturing low pressure-hardening cellular concrete - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: method comprises preparing blend between consecutively feeding and stirring in mixer: water with 40-60% (of its total amount) surfactant (0.5-1 min), silica component, cement, plasticizer, and the rest of surfactant. Blend is then stirred until pore formation thereof is completed. According to invention, silica component is added jointly with polyamide fibers 3-5 mm long, after which resulting combination is stirred for 2.5-4 min, the rest of surfactant and sodium aluminate are then added, and blend finely stirred. The following proportions of components are used, wt %: cement 43-90, silica component 5-45, surfactant 1-2, sodium aluminate 0.75- 2.5, plasticizer 0.5-1.5, fibers 2.75-6.0, and water 0.25-0.6. Concrete can be used to manufacture building parts and for in-place filling. EFFECT: increased crack resistance due to lowered shrinkage deformations and increased balanced life. 2 tbl, 6 ex

Description

The invention relates to building materials, and in particular to methods for preparing cellular concrete for the production of building products and for monolithic construction.

A known method of producing aerated concrete, comprising preparing a mixture by sequentially supplying a surfactant, water, a siliceous component and cement to a mixer, mixing and porizing in a mixer.

It is known from the patent literature that polyamide fibers are introduced into the foam concrete mixture to provide increased tensile strength (3).

However, the known method does not provide stable properties of concrete due to the uncertainty in the ratio of components, its multicomponent composition and the mode of introduction and mixing, which leads to uneven mixing, clumping, and as a result to an increase in bulk density and heterogeneity.

The closest is the method of producing aerated concrete by mixing the components and porous mixture in the mixer, while first, water is supplied to the mixer in an amount corresponding to a water-hard ratio of 0.18-0.23 and 40-60% surfactant, and 0.5- 1 min, then the siliceous component is introduced and mixed for 1-2 minutes, after which cement and plasticizer are added and mixed for 2-3 minutes, then the remaining surfactant is introduced and mixed until the mixture is completely porous. Moreover, as a surfactant, sodium sulfonate powder or sodium lauryl sulfate is introduced into the mixer in an amount of 0.8-2.0% by weight of cement, and C-3 in the amount of 0.2-0.4% by weight of cement is introduced into the mixer as a plasticizer .

The disadvantages of the known methods for producing cellular concrete is their limited scope due to the possibility of shrinkage deformations and the low strength of concrete, which leads to cracking.

The technical problem is to obtain porous concrete for monolithic construction of increased crack resistance by reducing shrinkage deformations and increasing equal strength.

The problem is solved in such a way that in the method for producing cellular concrete of non-autoclaved hardening, which includes preparing the mixture by sequentially supplying to the mixer and first mixing water with 40-60% surfactant - surfactant for 0.5-1 min, then the siliceous component then cement and plasticizer, followed by the introduction of the remaining part of the surfactant and mixing until the mixture is completely porous in the mixer, polyamide fibers 3-5 mm long are introduced together with the siliceous component and mixed into 2.5-4 min, then cement with a plasticizer is introduced and mixed for another 1-2 min, after which the remainder of the surfactant and sodium aluminate are fed and mixed until the mixture is completely porous, while the components are introduced into the mixer in the following ratio, wt.% :

Cement 43-90

Siliceous component 5-45

Surfactant 1-2

Sodium Aluminate 0.75-2.5

Plasticizer 0.5-1.5

Specified fibers 2.75-6.0

Water up to W / T 0.25-0.6

The proposed method differs from the known one by introducing a 3-5 mm length polyamide fibers with a siliceous component and a mixing mode.

The introduction of polyamide fibers together with the siliceous component and mixing for 2.5-4 minutes ensures their uniform distribution by weight and excludes the aggregation process, and provides the possibility of transportation and laying of the mixture with minimal shrinkage deformation.

Violation of the mode of preparation of aerated concrete mixture leads to the destruction of the structure and sediment of the mixture.

The method is as follows.

To prepare the aerated concrete mixture, Portland cement M 500 is used, silica component is quartz sand with a particle size 2.0, surfactants are TU-6-00-576-3650-86 sulfonate powder or TU-6-01-7-89 sodium lauryl sulfate, superplasticizer S-3 TU-6-36-020-4229-625-90, stabilizer - sodium aluminate, polyamide fibers GOST 22693-98.

A mixture is prepared with a water-solid ratio of 0.25-0.60. First, water and 40-60% surfactant are fed into the mixer and mixed for 0.5-1 min, then the siliceous component and fibers are fed into the mixer and the mixture is further mixed for 2.5-4.0 minutes, after which cement and plasticizer are introduced and mix 1.5-3 minutes The remaining surfactant and sodium aluminate are introduced into the resulting mixture and mixed until completely porous for 0.5-4 minutes.

Examples of the method and the physicotechnical properties of cellular concrete are shown in tables 1 and 2.

As can be seen from the tables, the proposed method provides for the production of non-autoclaved aerated concrete with high physical and technical properties, allowing it to be used both in monolithic construction and for the manufacture of products.

Sources of information

1. RF patent No. 2078749, cl. C 04 B 40/00, BI No. 13, 1997.

2. RF patent No. 2133722, cl. C 04 V 38/10, BI No. 21, 1999 (prototype).

3. RF patent No. 2132315, cl. S 04 V 38/10, BI No. 18, 1999.

Claims (1)

A method of producing non-autoclaved aerated concrete, comprising preparing the mixture by sequentially supplying to the mixer and first mixing water with 40-60% surfactant - surfactant, for 0.5-1 minutes, then a siliceous component, then cement and plasticizer, s subsequent introduction of the remaining part of the surfactant, and mixing until the mixture is completely porous, characterized in that polyamide fibers 3-5 mm long are introduced together with the siliceous component and mixed for 2.5-4 minutes, then cement is introduced from plas with a codifier and mixed for another 1-2 minutes, after which the remaining surfactant and sodium aluminate are fed and mixed until the mixture is completely porous, while the components are introduced into the mixer in the following ratio, wt.%: Cement 43-90 Siliceous component 5-45 Surfactant 1-2 Sodium Aluminate 0.75-2.5 Plasticizer 0.5-1.5 Specified fibers 2.75-6.0 Water up to W / T 0.25-0.6