RU2804960C2 - Raw mixture for manufacturing large format fire-retardant board and method for manufacturing large format fire-retardant board based on this mixture - Google Patents

Abstract

FIELD: construction materials.

SUBSTANCE: raw material mixture for the manufacture of large-format fire-retardant boards contains, wt.%: inorganic binder - Portland cement, or Portland slag cement, or Portland pozzolanic cement 38-50; as fillers, unfired siliceous rock with particle size of < 100 microns - diatomite, or zeolite, or opoka, or tuff, or volcanic ash 1.5-3; perlite 1.5-3; vermiculite 5-8; hydrated lime 2-7; fiber mixture 1.5-2.5; fire retardant - sodium tetraborate 0.2-0.5; additive accelerating the hardening of Portland cement - 1-2; air-entraining additive 0.01-0.05; plasticizing additive 0.01-1; mixing water - the rest. Fibre mixture - basalt fibre mixed with mullite and polypropylene fibres in a mass ratio of 2:10:2.5, respectively. In the method of manufacturing a large-format fire-retardant board, the specified board is obtained by preparing the above raw material mixture in a forced-type mixer by mixing the dry components of the raw mixture with mixing water and mixing the components of the raw mixture in a forced-type mixer, moulding in moulds by vibration casting, setting and hardening the said raw mixture in a chamber heat and humidity treatment. Hardening takes at least 10 days from the moment of pouring.

EFFECT: ensured fire resistance, high strength characteristics and thermal insulation properties of a large-format fire-retardant board, simplified technology for installing protective structures due to the large format and thickness of the board, and the possibility of using the resulting boards as ceiling boards.

5 cl, 3 tbl, 5 ex

Description

The invention relates to the building materials industry and is intended for fire protection of steel, reinforced concrete and reinforced cement structures in civil, industrial and rural construction.

Known fire retardant compositions based on Portland cement, gypsum, liquid glass, aluminous cement with various additives [Strakhov V.L., Garashchenko A.N. Fire protection of building structures: modern means and methods of optimal design // Construction materials. 2002. No. 6. pp. 2-5.; Copyright certificate of the USSR No. 275342. IPC E04B 1/94. Composition for coating metal elements / Shchipanov A.I., Labozin P.G. // BI No. 22, 07/03/1970; Guide to the compositions and use of thermal insulation and fire-resistant perlite plasters. M.: Stroyizdat, 1975. - 15 p.]. Expanded vermiculite and perlite are used as porous aggregates.

The technical problem of these compositions is the low crack resistance of the coating at high temperatures during a fire, the need for the use of gypsum and the relatively high thermal conductivity coefficient.

From patent RU2385851, published: 2010,04.10, a raw mixture for the manufacture of fire-retardant coating is known, including gypsum and porous fillers, characterized in that it contains expanded vermiculite and volcanic tuff sawing waste as fillers, which are both an active mineral additive, and as additives - quicklime and saponified wood resin in the following ratio of components, wt.%: gypsum 14.6-21.7 expanded vermiculite 33.4-50 sawing waste from volcanic tuff 22.5-33.3 quicklime 7.83- 11.5 saponified wood resin 0.07-0.1,

The technical problem with this composition is the need to use gypsum and the relatively high thermal conductivity coefficient.

Patent RU2689751, published: 05.28.2019, describes a fibrous facing mat for producing a gypsum panel. The fibrous mat contains at least one layer of nonwoven material and a binder composition. In this case, the binder composition is 10-40% wt. from the total mass of the mat. The binder composition contains a copolymer containing a comonomer unit of an alpha-branched aliphatic monocarboxylic acid vinyl ester, and said copolymer is present in an amount of 25 to 100% by weight. by weight of the binder composition. Provides improved adhesion characteristics between the gypsum core and the mat, while maintaining mechanical strength.

The technical problem of the prototype is that the panel has a three-layer structure, consisting of two outer layers of non-woven material and a gypsum panel core, while in the claimed invention the panel is single-layer based on a hydraulic binder - Portland cement and light fillers - perlite and vermiculite.

The analogue uses an air-hardening binder - gypsum with modified additives, which gives it water-resistant properties.

The declared panel and the analogue have similar features. First of all, these include water resistance. Also, both panels can be used for both external and internal work.

But, unlike its analogue, the claimed invention can be used as a structural fire-retardant and heat-insulating material to protect building structures and electrical cables.

Also, the analogue presents a very labor-intensive method for producing this product. Separately, non-woven material is produced for the outer layers of the product and the subsequent application of gypsum binder with modifying additives using the gluing process.

In addition, the analogue is not a structural material and metal or wooden frames or racks are required to support the specified gypsum panel. It is also not indicated that this panel can be used as a fireproof panel.

Known patent RU2597336, published: 2016.09.10, a known fiber-gypsum-vermiculite-concrete raw material mixture for the manufacture of a fire-retardant coating, including gypsum and porous aggregates, characterized in that it contains expanded vermiculite of a fraction of 0.16-5 mm and volcanic ash of a fraction of 0-0 as fillers .16 mm, which is at the same time an active mineral additive, and as additives - Portland cement, basalt fiber and saponified wood resin in the following ratio of components, wt.%: gypsum 40.0-47.7; expanded vermiculite 35.40-45.33; volcanic ash 3.0-3.5; Portland cement 10.0-12.1; basalt fiber 1.2-1.5; saponified wood resin 0.07-0.1.

The technical problem with all known solutions is that they use an air-hardening binder - gypsum - as the main component.

Gypsum is highly hygroscopic. Due to their porous structure, mineral raw materials absorb large amounts of water. This property limits the use of building gypsum in damp environments.

Also, gypsum has low moisture resistance. As a result of getting wet, there is a high probability of deformation of panels made from such materials.

When laying reinforcement inside the panels, you cannot use metal reinforcement due to possible corrosion, and when using natural fibrous materials - wood, reeds, etc., such panels will not have fire-retardant properties.

Gypsum has low strength due to its porous structure. Gypsum coating is easy to scratch, and sometimes you don’t even need tools to do it.

Thus, gypsum panels are ineffective as fire retardant materials because:

- due to their fragile structure, they cannot be installed on the ceiling, because in the event of a fire and subsequent flooding of such panels with water, under the influence of their weight with water, they will break and fall to the floor, which can cause injury to people;

- during the summer period of high humidity, gypsum panels absorb moisture and increase their weight, and due to their fragile structure they cannot be installed on the ceiling, because there is a risk of them breaking and falling down, which can cause injury to people.

The closest analogue is a fire-retardant fibrovermiculite-pumice-concrete raw mixture (RU2671010, published: 10/29/2018), including Portland cement, porous aggregates, water and additives, characterized in that it contains expanded vermiculite fraction 0.63-5 mm and volcanic pumice fraction as fillers 0-0.63 mm, which is at the same time an active mineral additive, and as additives - quicklime, building gypsum, basalt fiber and saponified wood resin in the following ratio of components, wt.%:

Portland cement 8.4-13.2 expanded vermiculite fraction 0.63-5 mm 10.23-13.25 volcanic pumice fraction 0-0.63 mm 21.86-25.44 saponified wood resin 0.08-0.13 quicklime 8.1-13.3 building gypsum 0.4-0.6 basalt fiber 1.0-1.5 water rest

The disadvantages of this composition are a different purpose of use, high cost and relatively low compressive strength.

The objective of the invention is to create a large-format fireproof panel with no less fire resistance, which does not contain gypsum as the main substance and can also be used as ceiling panels.

The technical result of the invention is to ensure fire resistance and simplify the technology for installing protective structures due to the large format and thickness of the slab, its ability to be used as ceiling slabs. In addition, high strength characteristics and thermal insulation properties are provided, which make it possible to reliably protect and protect building structures from the effects of heat flow and flame.

The specified technical result is achieved due to the fact that a raw material mixture is claimed for the manufacture of large-format fire-retardant boards, including as fillers unburnt siliceous rock with a particle size of <100 microns, Portland cement, basalt fiber, characterized in that Portland cement is used as the main substance of the mixture, also contains mixing water, a lightweight filler from the group of silica-aluminate rocks with a particle size of 0.5-1.5 mm and a volumetric weight of 40-60 kg/m ³ , a lightweight filler from the hydromica group with a particle size of 1-3 mm and a volumetric weight of 120-150 kg/ ^m3 , hydrated lime, fire retardant, additive that accelerates the hardening of Portland cement, air-entraining additive, plasticizing additive, as well as a mixture of mineral and organic fibers: basalt fiber, mullite fiber, polypropylene fiber, selected in the ratio 2:10:2.5, accordingly, with the following ratio of components, wt.%:

- Portland cement - 38-50%;

- unburnt siliceous rock with particle size < 100 microns - 1.5-3%;

- lightweight aggregate from the group of silica-aluminate rocks with a particle size of 0.5-1.5 mm and a volumetric weight of 40 - 60 kg/m ³ - 1.5-3%;

- lightweight aggregate from the hydromica group with a particle size of 1-3 mm and a volumetric weight of 120-150 kg/m ³ - 5-8%;

- hydrated lime - 2-7%;

- mixture of mineral and organic fibers - 1.5-2.5%;

- fire retardant (sodium tetraborate) - 0.2-0.5%;

- additive accelerating the hardening of Portland cement - 1-2%;

- air-entraining additive - 0.01-0.05%;

- plasticizing additive - 0.01-1%;

- mixing water - the rest.

It is acceptable that Portland cement is used as an inorganic binder - Portland cement without additives, or as Portland slag cement, or as Portland cement with pozzolanic additives, or as the described mixtures based on Portland cement.

It is acceptable that diatomite, or zeolite, or opoku, or tuff, or volcanic ash is used as an unburnt siliceous rock.

It is acceptable that sodium alpha-olefin sulfonate is used as an air-entraining additive.

Also claimed is a method for manufacturing a large-format fire-retardant board based on the above mixture, in which the board is obtained by mixing the above-described components of the mixture with water, mixing in a forced-type mixer and molding by vibration casting; Hardening of the mixture is carried out in a heat and humidity treatment chamber.

Preferably, after preparing the concrete solution in a forced-type mixer by mixing the components with water, the finished solution is unloaded into a mold measuring 1240×2040 mm through an intermediate hopper.

Preferably, the process of setting and hardening of the solution is carried out in cassettes of 9 forms, assembled on top of each other, then the cassettes are beaded, and the slabs are sent for additional drying.

Preferably, the concrete hardening process is maintained for at least 10 days from the moment of pouring.

Carrying out the invention

The declared composition of the raw material mixture for the manufacture of large-format fire-retardant boards is selected at the following ratio of components, wt.%:

- inorganic binder - Portland cement without additives, or Portland slag cement, or Portland cement with pozzolanic additives, or mixed Portland cement - 38-50%;

- unburnt siliceous rock with a particle size < 100 microns, for example, diatomite or zeolite, or opoka, or tuff, or volcanic ash - 1.5-3%;

- lightweight aggregate from the group of silica-aluminate rocks with a particle size of 0.5-1.5 mm and a volumetric weight of 40 - 60 kg/m ³ - 1.5-3%;

- lightweight aggregate from the hydromica group with a particle size of 1-3 mm and a volumetric weight of 120-150 kg/m ³ - 5-8%;

- alkaline component - hydrated lime - 2-7%;

- a mixture of mineral and organic fibers - 1.5-2.5% in the ratio: basalt fiber 2 parts, mullite fiber - 10 parts, polypropylene fiber - 2.5 parts;

- fire retardant - sodium tetraborate - 0.2-0.5%;

- additive accelerating the hardening of Portland cement - 1-2%;

- air-entraining additive - 0.01-0.05%, for example, sodium alpha-olefin sulfonate, tricalcium silicate or tricalcium aluminate;

- plasticizing additive - 0.01-1%, for example, polycarboxylate hyperpstifier TS -090, DOA - dioxyldipinate, 3G8 - triatilen glycol diocytate, Duo1, Duo2, TOTM - trioxylitrimilitis, DOP - diOxilate, GPO - diettylhexille Nonalftalat;

- mixing water - the rest.

The plate is produced by mixing the components of the mixture with water, mixing in a forced-type mixer and molding in molds using vibration casting. The mixture is hardened in a heat and humidity treatment chamber. The final set of brand strength of the product is produced under natural conditions.

The production of large-format fire-retardant boards is carried out in a manner reflected in the following example.

First of all, raw material sheds are prepared according to the technical map. Next, the concrete solution is prepared in a forced-type mixer by mixing the components with water.

Then, the finished solution is unloaded into a mold measuring 1240x2040 mm through an intermediate hopper. Next, the solution is distributed and leveled into shapes using a mechanical rule.

Setting and hardening of the solution can be carried out in cassettes of 9 forms, stacked on top of each other. Then the cassettes are flattened, and the slabs are sent for additional drying.

After the concrete hardening process is completed, which is approximately 10 days from the moment of pouring, the slabs are sent for cutting and grinding of the outer surface.

The stage of mechanical processing of the surface of the slab is followed by packaging of the finished slabs on pallets.

Using the above method, based on the above-described composition of the raw material mixture, a large-format fire-retardant board is obtained, which has the following construction and technical characteristics reflected in Table 1.

Table 1. Volume weight 550-950 kg/m ³ Compressive strength 1.5-5 MPa Flexural strength 0.8-2.4 MPa Water absorption in 2 hours 5-11% Size Length 1200 - 2400 mm
Width 1000-1200 mm
Thickness 30-50 mm

The choice of ingredients of the declared composition of the mixture and their quantity in the mixture is determined by the following.

The main active ingredient used is an inorganic binder - Portland cement. It was experimentally established that its lower content (less than 38%) leads to unacceptably low mechanical strength in both compression and bending. Meanwhile, higher (more than 50%) content resulted in a high bulk density of the slab, which resulted in poor thermal insulation and fire retardant properties of the slab.

The use of unfired siliceous rock in the mixture increases the fire resistance of the slab, increases the heat-insulating properties, and slows down the rate of temperature increase during fire exposure by releasing chemically bound water. It was experimentally established that a lower content - less than 1.5% in the composition of the mixture of unfired siliceous rock does not increase the fire-retardant properties, and more than 3% leads to a deterioration in the strength characteristics of the slab.

Lightweight filler from the group of silica-aluminate rocks also provides the thermal insulation properties of the slab. It was experimentally established that a lower (less than 1.5%) content of lightweight aggregate from the group of silica-aluminate rocks leads to a decrease in thermal insulation properties, and a higher (more than 3%) content leads to a decrease in the mechanical strength of the slab.

In the composition of the mixture, it was also necessary to use a lightweight filler from the hydromica group, which provided compaction (compression of the mixture components). At the same time, it was experimentally established that a lower content (less than 5%) helps to increase the volumetric mass of the slab, and a higher content (more than 8%) leads to a decrease in mechanical strength.

A mixture of mineral and organic fibers is used in the mixture as reinforcing components. Reducing their content to values less than 1.5% leads to the disappearance of the effect of fiber reinforcement (increasing mechanical strength and fire resistance), and increasing their content above 2.5% led to a deterioration in manufacturability and homogeneity of the composition in the production of the slab.

A functional additive is a hardening accelerator for Portland cement, used to accelerate setting, without which it is impossible to ensure a sufficient level of strength. It was experimentally established that an accelerator content of less than 1% does not allow the technological process to be carried out due to insufficient early mechanical strength, and increasing it to values of more than 2% leads to a deterioration in the workability of the mixture, an increase in porosity and, as a consequence, a deterioration in the strength characteristics of the slab .

The presence of a fire retardant (sodium tetraborate) in the composition increases the fire retardant properties of the slab. It has been experimentally determined that exceeding the maximum permissible ingredient limit of 0.5% will lead to a rapid loss of concrete workability. And in the case of fire retardant release beyond the minimum limit of 0.2%, the product loses its fire retardant properties.

The air-entraining additive promotes wetting of the mixture components and better workability. If more than 0.03% of the ingredient is used, the strength of the manufactured product is lost; if less than 0.03%, the air-entraining additive does not fulfill its properties.

The plasticizing additive improves the workability of the mixture and, by reducing the amount of mixing water, increases the strength of the product and reduces the hardening time. It was experimentally established that if more than 0.03% is added, the concrete mixture will separate, and with values less than 0.03%, the plasticizing effect disappears.

Thanks to the specified percentage of components and their ratio, the slab is a non-flammable composite system with high strength characteristics and thermal insulation properties that make it possible to reliably protect and protect building structures from the effects of heat flow and flame. The declared concentration limits are determined by the need to obtain a positive technical effect, since going beyond the specified limits leads to a decrease in the properties of the slab.

Examples of the invention of the proposed composition of the raw material mixture for the manufacture of large-format fireproof boards for structural fire protection of building structures are shown in Table 2.

Table 2. wt.% Mixture ingredients Example 1 Example 2 Example 3 Example 4 Example 5 Inorganic binder:
- Portland cement m500 D20
- Portland slag cement m400
- pozzolanic Portland cement 43.3 38 48 47 50 Alkaline component - hydrated lime 2 3 5 6 7 Unfired siliceous rock with particle size < 100 µm:
- diatomite
- zeolite
- flask
-tuff
- volcanic ash 2.10 5 2 3 1.5 Lightweight aggregate from the group of silica-aluminate rocks - perlite with a particle size of 0.5-1.5 mm and a volumetric weight of 40 - 60 kg/m ³ 1.5 3 2.5 2 2.4 Lightweight aggregate from the hydromica-vermiculite group with a particle size of 1-3 mm and a volumetric weight of 120-150 kg/ ^m3 6.5 7.2 7.5 8 5 Blend of mineral and organic fibers 1.8 1.8 1.5 2.2 2.5 Fire retardant - sodium tetraborate 0.34 0.44 0.2 0.3 0.5 Additive, hardening accelerator for Portland cement 1.15 2 1.55 1.85 1 Air-entraining additive:
- sodium alpha-olefin sulfonate
- tricalcium silicate
- tricalcium aluminate 0.03 0.03 0.02 0.01 0.05 Plasticizing additive:
- polycarboxylate hyperplasticato TS-090
- DOA - dioctyl adipate
- 3G8 - triethylene glycol dioctate
- TOTM - trioctyl trimylitate
- DOP - dioctyl phthalate 0.03 0.03 0.05 1 0.01 Water seal 41.25 39.5 31.68 28.64 30.04

The technical characteristics of the slabs obtained according to examples 1 - 5 were studied and their parameters are reflected in table 3.

Table 3. Example 1 Example 2 Example 3 Example 4 Example 5 Volumetric weight - density kg/m ³ 780 550 940 880 950 Compressive strength MPA 3 1.5 5 2.4 3.5 Flexural strength MPA 1.6 0.8 2.4 2.2 1.9 Water absorption in 2 hours % 7 eleven 5 6 5 Thermal conductivity W/(m*K) 0.34 0.17 0.45 0.28 0.37 Slab size 1200 × 1000 × 45 mm

From Table 3 it can be seen that all the boards obtained from examples 1, 2, 3, 4, 5 have increased fire resistance and weather resistance of the fire-retardant board.

Consequently, the problem of the invention was solved and a raw material mixture was created to create a large-format fire-retardant panel with no less fire resistance than known gypsum panels, but which does not contain gypsum as the main substance and can also be used as ceiling panels, since it does not absorb moisture and have high strength.

Claims (6)

1. Raw mixture for the manufacture of large-format fire-retardant boards, containing inorganic binder, fillers, lime, basalt fiber, mixing water, characterized in that it contains hydrated lime, basalt fiber mixed with mullite and polypropylene fibers in a mass ratio of 2:10:2, 5, respectively, as an inorganic binder, Portland cement, or slag Portland cement, or pozzolanic Portland cement, as fillers, unburnt siliceous rock with a particle size of <100 microns - diatomite, or zeolite, or opoku, or tuff, or volcanic ash, lightweight filler from the group of silica-aluminate rocks with a particle size of 0.5-1.5 mm and a volumetric weight of 40 - 60 kg/m ³ - perlite, lightweight aggregate from the hydromica group with a particle size of 1-3 mm and a volumetric weight of 120-150 kg/m ³ - vermiculite, fire retardant - sodium tetraborate, an additive that accelerates the hardening of Portland cement, an air-entraining additive, a plasticizing additive in the following ratio of components, wt.%: specified inorganic binder 38-50 diatomite, or zeolite, or opoku, or tuff, or volcanic ash 1.5-3 perlite 1.5-3 vermiculite 5-8 hydrated lime 2-7 specified fiber blend 1.5-2.5 sodium tetraborate 0.2-0.5 additive that accelerates the hardening of Portland cement 1-2 air-entraining additive 0.01-0.05 plasticizing additive 0.01-1 mixing water rest 2. The raw material mixture according to claim 1, characterized in that sodium alpha-olefin sulfonate is used as an air-entraining additive. 3. A method for manufacturing a large-format fire-retardant board, in which the specified board is obtained by preparing the raw material mixture according to claim 1 in a forced-type mixer by mixing the dry components of the raw mixture according to claim 1 with mixing water and mixing the components of the raw mixture according to claim 1 in a forced-type mixer , molding in molds by vibration casting, setting and hardening of the specified raw material mixture in a heat and humidity treatment chamber, and hardening is carried out for at least 10 days from the moment of pouring. 4. The method according to claim 3, characterized in that after preparing the raw material mixture according to claim 1 in a forced-type mixer, it is unloaded into a mold measuring 1240×2040 mm through an intermediate hopper. 5. The method according to claim 3, characterized in that the setting and hardening of the raw material mixture according to claim 1 is carried out in cassettes of 9 forms, assembled on top of each other, then the cassettes are beaded, and the slabs are sent for additional drying.