RU2291846C1 - Fibro-cement compound for production of composite material - Google Patents

Abstract

FIELD: manufacture of building materials.

SUBSTANCE: proposed fibro-cement compound contains the following components, parts by mass per 100 parts by mass of cement: cement binder, sand, 20-30; reinforcing fibers, 0.8-6; acryl copolymer emulsion "ACREMOS-512", 3-10; plasticizing additive- super-plasticizing agent on base of naphthalene sulfonic acid and formaldehyde "C-3", 0.5-1.5; pigment, 3-5 and water, 15-30; it additionally contains surfactant-foaming agent "PIONEER-128" for swelling-up of dispersed fiber; defoamer "PENTA-471" in the amount of 0.03-0.8 is additionally introduced for reduction of number of air pores. Invention makes it possible to obtain easily moldable molding sand at enhanced physico-mechanical properties for obtaining dense and strong decorative facing and decorative heat-insulating articles: slabs for facing the buildings and double-layer decorative heat-insulating slabs with warmth-keeping lagging molded onto composite fibro-cement material for forming ventilated front of building.

EFFECT: enhanced efficiency.

2 cl, 2 tbl, 3 ex

Description

The invention relates to the building materials industry, in particular to mixtures and compositions for the production of composite fiber cement material, and can be used in the manufacture of protective decorative products from this material, and, if necessary, two-layer decorative and heat-insulating plates for facing facades and ventilated building facades during construction and repair of monolithic reinforced concrete buildings and other structures of housing, industrial and civil construction.

Known raw material mixture for the production of structural heat-insulating material (see patent RU No. 2243179, class MKI C 04 B 28/14, bull. No. 36, 12/27/2004), including two-water gypsum and slag Portland cement as a binder, slaked lime, water , organic aggregate and alum.

The disadvantages of this mixture are low physical and mechanical properties and the inability to use for outdoor products.

A known mixture for composite materials based on cement binder according to the method of preparation of the mixture (see patent RU No. 2165399, class MKI C 04 B 40/00, 04/20/2001) by mixing cement and based on 100 parts by weight cement 20-100 parts by weight microfill, 30-50 parts by weight water, 0.05-0.5 parts by weight plasticizing additives and 0.5-5 wt.h. synthetic fiber, in this case, before mixing, the reinforcing fibers are preliminarily subjected to mechanochemical activation (fluff) in high-voltage apparatuses in a mixture with a filler and an aqueous solution of a plasticizing additive.

The disadvantages of this mixture are low indices of workability of the molding mixture, grinding and uneven distribution of the reinforcing fiber over the volume of the mixture and, as a result, the variation in the strength characteristics of the resulting composite material.

Known decorative composite material based on cement binder (patent RU No. 2133236, class MKI S 04 B 26/04, bull. No. 20, 07/20/1999), including white cement, stone chips, crushed mica and water, with high strength characteristics and adhesion through the use of acrylic polymers.

A disadvantage of the known decorative composite material is its low frost resistance.

The closest in technical essence and the achieved effect, selected as a prototype, is a polymer-cement composition (see patent RU No. 2164899, class MKI C 04 V 26 / 02.10.04.2001) containing Portland cement, mineral fillers, water and a polymer additive with the following content of components, wt.%: Portland cement - 16-32, mineral fillers - 45-60, water - 14.8-21.5, plasticizer - 0.5-1.2 and polymer additive - 1.0-6 , 0. The introduction of a polymer additive increases the compressive strength and reduces water absorption, which can be further confirmed by the use of acrylic polymers to improve the physicomechanical properties of building materials, such as sand concrete for various purposes and plasters, including decorative (see patent RU No. 2111321, class MKI C 04 B 28/04, 05.20.1998).

The disadvantages of the known polymer-cement composition include the small effect of the introduction of polymer additives on increasing water resistance and frost resistance, as well as on the density of the material.

The aim of the invention is the selection and quantification of the components of the fiber cement composition to obtain a composite fiber cement material having high workability, formability and having high strength, frost and water resistance, providing dense and durable decorative products, for example, building elements of relatively small thickness - plates with high-quality front surface for facing buildings and two-layer decorative thermal insulation slabs with a molded slab insulation to the composite fiber-cement material of the decorative-facing layer for use in the construction of ventilated building facades.

These problems are solved according to the invention in that the fiber cement composition for producing a composite material containing cement binder, sand, reinforcing fibers, acrylic polymer, plasticizing additive, pigment and water, additionally contains a surface-active substance (SAS) to improve the dispersion of the fiber, and to reduce the number of air pores - defoamer in the following ratio of components, parts by weight per 100 parts by weight cement, while a plasticizer based on naphthalene sulfonic acid and C-3 formaldehyde is used as a plasticizing agent, Pioneer-128 foaming agent is used as a surfactant, Penta-471 antifoam is used as an antifoam, and acrylic polymer is used use the emulsion of acrylic copolymers "Akramos-512":

Sand 20-30 Plasticizer "S-Z" 0.5-1.5 Reinforcing fibers 0.8-6 Pigment 3-5 Acrylic polymer "Akramos-512" 3-10 Surfactant "Pioneer-128" 0.01-0.03 Antifoam Penta-471 0.03 - 0.8 Water 15-30

Moreover, in the fiber cement composition to obtain a composite material, glass fibers with a length of 12 mm and 6 mm are used as a reinforcing fiber in a ratio of 30% and 70%, respectively.

The essence of the invention lies in the fact that these features are significant due to new technical, operational and economic effects.

So, the claimed technical solution, unlike the known ones, offers a new elemental composition of the molding mixture, according to which the fiber cement composition to obtain a composite material additionally contains a surfactant - a synthetic foaming agent, an aqueous solution of anionic surfactants "Pioneer-128" according to TU 2481-185-05744685 as a dispersant for better dispersion fiber dispersion and Penta-471 water-soluble silicone antifoam according to TU2257-001-40245042-98 to increase the density and remove air bubbles. Improving the workability of the molding sand is ensured by introducing part of the sand (up to 20%) instead of cement, using the S-3 superplasticizer, which is a mixture of naphthalene sulfonic acids with formaldehyde and sodium lignosulfonic acid neutralized with sodium hydroxide according to TU 5745-004-43184789- 05, and Acramos-512 acrylic polymer, which is a copolymer of acrylic and methacrylic acid esters, obtained by the emulsion method according to TU 2241-262-05757593-2000, which has plasticizing properties, and optimization of the composition. Increasing the strength, water resistance and frost resistance of the hardened composite of products is achieved through the use of the selected acrylic copolymer of the specified mass content in this mixture containing fiber, having high water resistance, elasticity and strength of hardened products, clogging pores, and a minimum water content. In addition, the addition of sand increases workability, reduces the water-cement ratio (w / c) and improves the conditions for fiber drying.

Thus, the hallmarks of the claimed fiber cement composition to obtain a composite material are its new elemental composition with an additional content of surfactant and antifoam, as well as the indicated optimal ratio of components.

The applicant does not know the fiber cement composition for producing a composite material with the indicated combination of essential features and the claimed combination of essential features does not follow explicitly from the current level of technology, which confirms the compliance of the claimed invention with the criteria of "novelty" and "inventive step".

The invention is illustrated by examples of its implementation, where the compositions of the molding sand are given in table 1, and the results of physical and mechanical tests of samples prepared from these mixtures are presented in table 2.

The molding mixture for preparing the composite material is prepared as follows: observing the following introduction order and the indicated ratio of components, the liquid component of the molding mixture is first prepared in the mixer-activator from water, a plasticizing agent, surfactant, pigment, sand and reinforcing fibers and the fiber is fluffed, then the mixture is injected with an acrylic polymer, an antifoam and a cement binder (Portland cement or white cement). The mixture is mixed until the desired working consistency is obtained and fed to molding for the manufacture of decorative-facing or decorative-heat-insulating products in the form of two-layer plates, where a plate insulation is laid on a layer of the molding mixture. After molding, the plates are heat treated in molds.

The use of the invention within the framework of the proposed formulation and the sequence of loading components into the mixer will make it possible to obtain workable molding mixtures, and hardened material with improved physical and mechanical properties, frost resistance and water resistance, providing dense and durable decorative-facing and decorative-thermal insulation products, including . relatively small thickness of building elements - plates with a high-quality front surface for building cladding and two-layer decorative heat-insulating plates with a molded plate insulation to the composite fiber cement material of the decorative facing layer for use in the construction of ventilated building facades.

Table 1 Name of components The ratio of components in parts by weight in examples one 2 3 Analogue No. 2165399 Prototype No.2164899 Portal cement one hundred one hundred one hundred one hundred one hundred Microfiller - - - twenty 60-240 Sand 25 25 25 15-100 64-140 Dispersed fiber 4.3 2,5 2.0 0.5-5.0 - Acrylic emulsion 5,0 8.9 8.0 - 7.1-25 Plasticizer 1,1 1,0 0.7 0.05-0.5 2.0-3.75 Surface-active substance 0.015 0.01 0.02 Antifoam agent 0.3 0.3 0.4 - - Water 25 23 twenty 30-50 46-134 table 2 The name of indicators The values of the indicators in the examples one 2 3 Analogue No. 2165399 Prototype No.2164899 Density, kg / m ³ 1689 1745 1770 1980-2150 - Compressive strength, MPa 36.7 43.9 39.7 28.5-38.9 Bending Strength, MPa 16,0 17.8 15.1 19.5-37.8 Water absorption,% 3.6 3.0 2,3 - - Frost resistance cycle 300 300 300 - -

Claims (2)

1. Fiber-cement composition to obtain a composite material containing cement binder, sand, reinforcing fibers, acrylic polymer, plasticizing agent, pigment and water, characterized in that it additionally improves the dispersion fiber dispersion of the surface-active substance (surfactant), and for reduce the number of air pores defoamer in the following ratio of components, parts by weight per 100 parts by weight cement, while a plasticizing agent based on naphthalene sulfonic acid and C-3 formaldehyde is used as a plasticizing agent, Pioner-128 foaming agent is used as a surfactant, Penta-471 antifoam is used as an antifoam, and an emulsion is used as an acrylic polymer acrylic copolymers "Akramos-512": Sand 20-30 Reinforcing fibers 0.8-6 Acrylic polymer "Akramos-512" 3-10 Water 15-30 Plasticizer "S-3" 0.5-1.5 Pigment 3-5 Surfactant "Pioneer-128" 0.01-0.03 Antifoam Penta-471 0.03-0.8 2. The fiber cement composition for producing a composite material according to claim 1, characterized in that glass fibers with a length of 12 mm and 6 mm are used as reinforcing fibers in a ratio of 30% and 70%, respectively.