RU2811704C1 - Raw mixture for fire retardant plaster mortar - Google Patents

Abstract

FIELD: construction materials.

SUBSTANCE: invention can be used by construction organizations for fire protection of building structures. The raw mixture for fire-retardant plaster mortar includes components in a dry mixture in the following ratio, wt.%: gypsum 12.8 – 32.0, expanded vermiculite 27.0 – 36.0, volcanic ash 36.9 – 47.1, Portland cement 3.2 – 7.0, D-5 0.9 – 1.1.

EFFECT: improved physical and mechanical properties of fire retardant solutions.

1 cl, 3 tbl

Description

The invention relates to the building materials industry and can be used by construction organizations for fire protection of concrete, reinforced concrete and metal structures.

Fire-retardant compositions based on Portland cement, gypsum, liquid glass, aluminous cement with various additives are known [1, 2, 3]. Expanded vermiculite and perlite, expanded clay are used as porous fillers.

A known fiber-gypsum-sovermiculite-concrete raw material mixture for the manufacture of fire-retardant coatings [4], containing, by weight. %: gypsum 40.0 – 47.7; expanded vermiculite 35.40 – 45.33; volcanic ash 3.0 – 3.5; Portland cement 10.0 – 12.1; saponified wood resin 0.07 – 0.1; basalt fiber 1.2 – 1.5. These concrete compositions are difficult or impossible to apply to building structures under site conditions and are expensive.

The closest are fire-retardant plaster mixtures using gypsum, expanded perlite, granulated mineral wool [5].

The disadvantages of these compositions are the increased consumption of gypsum, the difficulty of preparing and applying the mixture with granulated mineral wool, the high cost and relatively low strength of the fire-retardant plaster mortar.

The purpose of the invention is to reduce the specific consumption of gypsum, expand the raw material base, increase the strength and reduce the cost of the fire-retardant plaster mortar.

The problem is solved by using gypsum, Portland cement, expanded vermiculite, volcanic ash and a complex modifying additive D-5 in the fire-retardant plaster raw material mixture.

Portland cement PC500-DO produced by Belgorod Cement JSC and gypsum grade G-5 BII were used in the experiments. Volcanic ash of the Zayukovskoe deposit of fraction 0-0.315 mm was used as an active mineral additive.

The chemical composition of volcanic ash is presented in Table 1.

Table 1

Content of main components in% by weight _{SiO2 Al2O3 _ Fe2O3 _} CaO MgO TiO Na ₂ O+ +K ₂ O SO ₃ p.p.p. 73.1 13.75 1.75 1.65 1.12 0.23 3.87 0.12 2.0

The filler is expanded vermiculite from the St. Petersburg mica factory with a bulk density of 150 kg/m ³ with a maximum grain size of 2.5 mm.

The granulometric composition of expanded vermiculite is given in table. 2.

table 2

Granulometric composition of vermiculite

Name of material Partial residues on sieves, % Passed through the sieve 0.14 1.25 0.63 0.315 0.14 Vermiculite 67.4 13.5 8.7 6.1 4.3

To regulate the technological properties of the mortar mixture, additive D-5 was used, produced by NPP Irstroyprogress LLC (Vladikavkaz), which has multifunctional properties.

To prepare the mixture, the calculated amount of components was weighed out. The mixture was prepared in a forced-action mixer, into which gypsum, Portland cement, volcanic ash, expanded vermiculite were sequentially loaded and mixed until a homogeneous dry mixture was obtained, then water from D-5 was added and mixing continued until a homogeneous mortar mixture was obtained.

The study of the properties of mortar mixtures was carried out according to GOST 5802-86 and their compliance with the requirements was determined according to GOST 28013–98.

Samples measuring 4 × 4 × 16 cm were molded by injection molding and naturally dried under air-dry conditions.

The flexural strength of fire retardant solutions was determined on the MII-100 device on the 28th day.

The compositions of the raw material mixture for fire-retardant plaster mortar according to the invention and the physical and mechanical properties of fire-retardant solutions are given in Table 3.

Table 3

Compositions Content in the dry mixture, % of its mass Physical and mechanical characteristics
fire retardant solutions gypsum mineral wool granulated perlite vermi-
kulit Portland-
cement ash additive D-5 average density, kg/m ³ bending strength (MPa) compressive strength (MPa) Prototypes 1 85 2.6 12.4 – – – – 600 0.6 1.0 2 76 7 17 – – – – 500 0.5 0.7 3 59 16 25 – – – – 450 0.3 0.6 Developed fire-retardant plaster mixtures 4 35.0 – – 27 – 36.9 1.1 590 1.1 1.6 5 28.0 – – 27 7.0 36.9 1.1 600 1.4 2.2 6 23.0 – – 32 – 44.0 1.0 488 0.7 1.1 7 18.4 – – 32 4.6 44.0 1.0 506 0.8 1.3 8 16.0 – – 36 – 47.1 0.9 443 0.6 0.9 9 12.8 – – 36 3.2 47.1 0.9 457 0.7 1.2

From Table 3 it can be seen that with a significantly lower consumption of gypsum and at approximately the same density, the developed fire-retardant plaster solutions have higher bending and compressive strengths. This is explained by the fact that fine ash fractions are a chemically active component, unlike granulated mineral wool used in the prototype.

Additive D-5 has a positive effect on the rheological properties of the mixture, increases the strength and reduces the density of the fire-retardant plaster mortar.

The developed fire-retardant plaster compositions provide a significant reduction in their cost by reducing the consumption of gypsum and expensive granulated mineral wool compared to prototypes.

Information sources

1. Strakhov V.L., Garashchenko A.N. Fire protection of building structures: modern means and methods of optimal design // Construction materials. 2002. No. 6. P. 2 – 5.

2. Copyright certificate of the USSR No. 275342. IPC E04B1/94. Composition for coating metal elements / Shchipanov A.I., Labozin P.G. // B.I. No. 22, 07/03/1970.

3. Guide to the composition and use of heat-insulating and fire-resistant perlite plasters. M.: Stroyizdat, 1975. – 15 p.

4. Hezhev T.A., Mataev T.Z., Hezhev Kh.A. RF Patent No. 2597336. Fiber-gypsum-supermiculite-concrete mixture for the manufacture of fire-retardant coating // Bull. No. 25. 2016.

5. Guidelines for making fire-retardant and heat-insulating plasters using a mechanized method. M.: Stroyizdat, 1977. – 46 s.

Claims (2)

Raw mixture for fire-retardant plaster mortar, including gypsum, porous fillers and additives, characterized in that it contains expanded vermiculite and volcanic ash as porous fillers, while volcanic ash is also an active mineral additive, and Portland cement and D are used as additives -5 with the following ratio of components in the dry mixture, wt. %: gypsum 12.8 – 32.0 expanded vermiculite 27.0 – 36.0 volcanic ash 36.9 – 47.1 Portland cement 3.2 – 7.0 D-5 0.9 – 1.1