RU2318778C2 - Method of preparation of mix for production of composite material and method of manufacture of articles from such composite material - Google Patents

Abstract

FIELD: manufacture of building materials; preparation of mixes for production of composite materials; facing the building fronts including fibrous cement large-sized slabs.

SUBSTANCE: proposed method includes mixing of 100 parts by mass of cement, 0.8-8 parts by mass of reinforcing fibers, 10 parts by mass of micro-filler, 0.5-1.5 parts by mass of plasticizing additive, 14-20 parts by mass of water, 3-10 parts by mass of acryl copolymer, 0.5-1.5 parts by mass of hardening agent for acryl copolymer and 3-5 parts by mass of mineral pigment. First, liquid component is prepared in activator-mixer from water, plasticizing additive, reinforcing fibers, acryl copolymer, acryl copolymer hardening agent and mineral pigment; then, reinforcing fiber is subjected to fluffing-up, after which micro-filler is introduced in the amount of 15-35% of total amount of cement required for preparation of mix. Then, liquid component is transferred to planetary mixer where it is mixed with cement or with its remaining part till working consistency of mix. Used as plasticizing additive is super-plasticizing agent C-3 on base of naphthalenesulfonic acid and formaldehyde; used as acryl copolymer is acryl monomer emulsion МБМ-5C; used as acryl copolymer hardening agent is lime; used as micro-filler is micro-silica at average diameter of granules of 0.3-3.0 mcm; used as reinforcing fibers are glass fibers at addition of 10-15% of fine asbestos fibers of Grade 4-5 or fluffed-up cellulose. For realization of this method, use is made of molds with flexible pans.

EFFECT: possibility of obtaining placeable and moldable mix; enhanced strength and density of articles made from this mix; smooth surfaces of articles.

7 cl, 1 tbl, 1 ex

Description

The invention relates to the building materials industry, in particular to the manufacture of a mixture for the production of composite materials and products from composite materials for cladding building facades, including fiber cement large-sized plates.

A known method of preparing a mixture to obtain a composite material based on cement binder by mixing cement, reinforcing fibers, microfiller, water, plasticizing additives containing 100 parts by weight cement 2-18 parts by weight reinforcing fibers, 5-25 parts by weight micro fillers, 20-35 parts by weight water and 2-4 parts by weight plasticizing additives, while the reinforcing fibers are added to the pre-mixed mixture of the remaining components, as well as products from composite material obtained from this mixture [see Russian Patent No. 2036886, С04В 40/00, publ. 06/09/95].

The disadvantages of this mixture are the low workability of the molding sand, the 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.

A known method of preparing a mixture to obtain a composite material based on a cement binder by mixing cement, reinforcing fibers, microfiller, water, plasticizing additives containing 100 wt.h. cement 0.5-5 parts by weight reinforcing fiber, 20-100 parts by weight filler, 30-50 parts by weight water, 0.005-5 parts by weight plasticizing additives, while the mixture of filler and reinforcing fibers before mixing with the rest of the components is subjected to mechanical activation in high-voltage apparatuses - centrifugal planetary or in vibration-centrifugal mills with acceleration of the impacting bodies of 80-600 m / s ² [see Russian Patent No. 2165399, С04В 40/00, publ. 04/20/2001].

The method allows to obtain high strength of the material, but is energy-intensive and, as a consequence, expensive, in addition, the method does not provide products with a smooth smooth surface and a uniform distribution of reinforcing fibers in the composite material.

The objective of the proposed technical solution is to create a method of preparing a mixture to obtain a composite material with high workability and formability, providing durable and dense products with a flat, smooth, as well as the front surface.

In addition, the proposed technical solution offers a method for producing decorative products from composite material, including decorative and decorative plates (sheets) of small thickness for facing facades of buildings. The composite material obtained from this mixture should be inexpensive, have elasticity, low water absorption and high water resistance along with high bending strength. The proposed method for manufacturing products from composite material should provide a smooth beautiful surface, high density and strength, and should also allow easy removal of products from the mold.

The specified technical result is achieved by the fact that in the method of preparing the molding mixture to obtain a composite material based on a cement binder by mixing cement, reinforcing fibers, microfiller, water, plasticizing additives, there are differences, namely, an acrylic copolymer, an acrylic copolymer hardener and mineral pigment, while per 100 parts by weight cement used 14-20 wt.h. water, 0.5-1.5 parts by weight plasticizing additives, 0.8-8 wt.h. reinforcing fibers, 3-10 parts by weight acrylic copolymer, 0.5-1.5 parts by weight hardener acrylic copolymer, 3-5 wt.h. mineral pigment, 10 parts by weight micro-filler, and first, in the activator-mixer, the liquid component of the mixture is prepared from water, a plasticizing agent, reinforcing fibers, an acrylic copolymer and hardener of an acrylic copolymer, a mineral pigment, the reinforcing fiber is fluffed, then a micro-filler or 15-35% of the total used preparing a mixture of the amount of cement, then the liquid component is pumped into a planetary mixer, where it is mixed with cement or the rest of it to a working consist ntsii mixture.

Moreover, a superplasticizer based on naphthalenesulfonic acid and formaldehyde (C-3) is used as a plasticizing additive [TU 2481-016-00369171-99].

As an acrylic copolymer, an MBM-5C emulsion of acrylic monomers is used [TU 6-01-186-89].

As the hardener of the acrylic copolymer, lime is used.

Silica fume with an average granule diameter of 0.3-3.0 microns is used as a micro-filler.

As a mineral pigment can be used red lead, ocher, etc.

In addition, if necessary, the introduction of anti-shrink additives up to 30% of the cement is replaced by tensile cement.

In addition, glass fiber with the addition of 10-15% fine fibers (asbestos or fluff pulp) is used as a reinforcing fiber.

The mixture prepared by the specified method for the manufacture of composite material allows one to make products from it from composite material and decorative and decorative plates of various colors, having great strength and a smooth surface. The acrylic copolymer used in the mixture allows to reduce the amount of water in the molding mixture to the minimum necessary for cement hydration, without reducing the workability of the mixture. The introduction of a hardener simultaneously with an acrylic copolymer allows you to increase the role of reinforcing fibers in increasing bending strength.

The introduction of mineral pigments allows us to expand the color gamut of the resulting materials and products.

The proposed sequence of loading components into mixers allows to obtain a uniform distribution of components in the mixture, which increases the strength of the resulting composite material and products from it.

The proposed method for producing products from composite material also allows to obtain decorative tiles with a smooth surface and various colors of large size and small thickness by molding from this mixture.

The proposed technical solutions are interconnected and form a single inventive concept.

Known methods for improving the formability of various building mixtures by introducing polymer additives.

For example, up to 6 parts by weight are added to the molding mixture. copolymer of vinyl acetate or vinyl chloride, or acrylate with hydroxypropyl methylcellulose [see Russian Patent No. 2164899, С04В 26 / 02.28 / 04, 24/22, 14/06, publ. 1990]. The introduction of these polymer additives increases the compressive strength, reduces water absorption, but has little effect on increasing the water resistance and frost resistance of the product.

It is known to use acrylic polymers to improve the physicomechanical properties of building materials, for example, sand concrete for various purposes and plasters, including decorative [see Russian patent No. 2111321, С04В 26/02, publ. 1997] and others.

However, the use of acrylic copolymers in mixtures containing fiber, designed to obtain particularly strong and dense products, is not known from the prior art.

In order to obtain products in the form of large-sized cladding plates, the proposed technical solution, along with a new method for producing the molding mixture, offers differences from the prototype in the molding conditions, namely that the product is manufactured on the molding conveyor by continuous molding, and the mixture is compacted using a sliding vibratory stamp and to orient the fibers along the long side of the product, the molding mixture is fed from the intermediate hopper under the influence of vibration and is pulled along the we.

In addition, in order to increase the strength and density of the products, the oscillation amplitude of the sliding vibro-stamp in its head is 0.5-0.6 mm, and in the tail 0.1-0.2 mm.

In addition, in order to remove air bubbles from the mixture during vibration compaction, a vacuum with a discharge of 600 mm of water column is created under the vibro-stamp.

In addition, in order to further seal the structure of the material, the molded products harden and self-seal in thermal packages under load.

In addition, forms with a flexible pallet are used to facilitate formwork.

The molding mixture to obtain a composite material is prepared as follows, observing the ratio of components indicated in the formula.

The mineral pigment is introduced into the tank with water and mixed, then a plasticizing agent is added there. The acrylic copolymer is mixed with an antifoam in another tank. Further, both mixtures are mixed in a special mixer-activator with reinforcing fiber, hardener of acrylic copolymer, and microfill or 15-35% of the total amount of cement used is added there after fluffing of the reinforcing fiber.

If necessary, the introduction of anti-shrink additives instead of portland cement is used tensile cement. The resulting liquid component of the mixture is fed into a planetary mixer, the rest of the cement is added there. As cement, depending on the desired color of the product, both Portland cement and white cement can be used - in this case, the color of the product will be determined by the pigment introduced into the mixture.

The mixture is mixed and fed to the molding for the manufacture of decorative materials. The manufacture of small products is possible by any known method of molding material.

If it is necessary to obtain large-sized facing plates, molding is carried out on the molding conveyor by continuous molding and compaction using a sliding vibro-stamp, while the molding mixture for orientation of the fibers along the long side of the product is fed under vibration from the intermediate hopper and pulled along the mold.

In this case, the amplitude of oscillations of the sliding vibratory stamp in its head part is 0.5-0.6 mm, and in the tail 0.1-0.2 mm. Under the vibration dampener to remove air bubbles from the moldable mixture, a vacuum is created with a discharge of up to 600 mm water column. To improve the removal of molding products, molds with a flexible pallet are used. After molding, the plates are subjected to heat treatment in thermal packages under load.

Example:

The compositions of the mixtures to obtain the molding mixture are given in table 1, and the results of physical and mechanical tests of samples made from these mixtures are given in table. 2.

Table 1 Name of components The ratio of components by weight in the examples. one 2 3 four 5 6 7 prototype 1 prototype 2 Portland cement one hundred one hundred 80 one hundred one hundred one hundred 80 one hundred one hundred Tensile cement - - twenty - - - twenty - - Microfiller - - - - - 10 10 10 - Sand - - - - - - - - 40 Dispersed Glass Fiber 2.60 3.71 1.34 0.86 6.83 7.51 6.80 9.0 2.0 Asbestos or fluff pulp - - - - - - 1.00 - - Acrylic emulsion MBM-5C 3.15 10.00 7.03 7.14 5.28 8.01 8.50 - - Acrylic Copolymer Hardener - Lime 0.50 1,50 1.00 1,07 0.67 1.21 1.38 - - Plasticizer "S-3" 0.53 0.53 1,07 0.94 1.48 0.81 1.35 2,5 0.2 Mineral pigment (minium) - - - - - - 4.20 - - Water 18.27 15.04 16.93 16,20 18.35 17.93 17.30 27.5 35.0

table 2 The name of indicators The values of the indicators in the examples. one 2 3 four 5 6 7 prototype 1 prototype 2 Plasticity of mixtures, see OK 6.0 9.0 7.0 7.5 7.0 8.0 8.0 - - Density, kg / l 1,67 1.84 2.07 1.73 1.70 1.80 1.98 1.59-2.36 1.65-2.15 Compressive strength, MPa 36.1 39.7 42.8 28.8 37.9 41.2 48.3 - - Bending Strength, MPa 17.3 22.4 27.8 25.1 21.3 24.2 28,4 11.15-29.63 19.5-35.3 Water absorption,% 3.8 1,6 2,3 2.7 3.0 2.1 1.8 - - Frost resistance cycle 150 150 150 150 150 150 200 - -

Claims (7)

1. The method of preparation of the mixture to obtain a composite material based on a cement binder by mixing cement, reinforcing fibers, micro-fillers, plasticizing additives, water, with the preliminary activation of the components of the mixture, characterized in that the mixture is additionally introduced acrylic copolymer, hardener of acrylic copolymer and mineral pigment, with 100 parts by weight cement use 14-20 wt.h. water, 0.5-1.5 parts by weight plasticizing additives, 0.8-8 wt.h. reinforcing fibers, 3-10 parts by weight acrylic copolymer, 0.5-1.5 parts by weight hardener copolymer, 3-5 wt.h. mineral pigment, 10 parts by weight micro-filler, and first, in the activator-mixer, a liquid component is prepared from water, a plasticizing agent, reinforcing fibers, an acrylic copolymer, an acrylic copolymer hardener and a mineral pigment, the reinforcing fiber is fluffed, then a micro-filler or 15-35% of the total used in the preparation is introduced mixture of cement, then the liquid component is pumped into a planetary mixer, where it is mixed with cement or its remaining part to a working consistency mixtures, in this case, a plasticizer based on naphthalene sulfonic acid and formaldehyde - “S-3” is used as a plasticizing additive, an emulsion of acrylic monomers MBM-5 C is used as an acrylic copolymer, lime is used as an acrylic copolymer hardener, microsilica with medium is used as a microfiller with a diameter of granules of 0.3-3.0 microns, glass fibers with the addition of up to 10-15% of fine asbestos fibers or fluff pulp are used as reinforcing fibers. 2. A method of obtaining a product from a composite material, comprising preparing a molding mixture to obtain a composite material and its subsequent molding, characterized in that the mixture is prepared according to claim 1. 3. A method of producing a product from a composite material according to claim 2, characterized in that the products are manufactured on a molding conveyor by continuous molding, the mixture being compacted using a sliding vibratory stamp, and for molding the fibers along the long side of the product, the molding mixture is fed from the intermediate hopper under the influence of vibration and pull it along the form. 4. The method according to claim 3, characterized in that the amplitude of the vibrations of the sliding vibro-stamp in its head part is 0.5-0.6 mm, and in the tail 0.1-0.2 mm. 5. The method according to claim 3 or 4, characterized in that during the vibration compaction, a vacuum is created under the sliding vibration damper with a discharge of 600 mm of water column. 6. The method according to claim 5, characterized in that the molded products harden and self-seal in thermal packages under load. 7. The method according to any one of claim 3 or 4, characterized in that use forms with a flexible pallet.