RU2301207C1 - Glass fibrous concrete (versions) - Google Patents

Abstract

FIELD: manufacture of building composite materials; glass fibrous mixes; construction engineering; permanent forms, decorative members, ventilated fronts.

SUBSTANCE: glass fibrous concrete mix contains cement, chemical additive, fine-grained sand, friable roving made from alkali-resistant glass fiber and water; chemical additive contains, mass-%: SiO₂, 88; plasticizing agent C-3,9-10; water, 2-3; alkali-resistant glass fiber has length from 21 mm to 40 mm at the following ratio of components, mass-%: cement, 48-53; chemical additive, 4-6; fine-grained sand,20-28; friable roving, 3-7; water, 13-17. According to another version, glass fibrous concrete mix contains cement, chemical additive, fine-grained sand, alkali-resistant glass fiber and water; chemical additive contains the following components, mass-%: SiO₂, 88; plasticizing agent C-3,9-10; water, 2-3; length of alkali-resistant glass fiber ranges from 21 mm to 40 mm at the following ratio of components, mass-%: cement, 45-57.5; chemical additive, 2-8; fine-grained sand,25-35; fiber, 0.5-9; water, 15-20.

EFFECT: enhanced compressive strength, tensile strength and tensile strength at bending; reduction of water permeability of mixes.

3 cl, 1 tbl, 5 ex

Description

The invention relates to building composite materials, more specifically to a mixture of fiberglass concrete, and can be used in construction, for example, as a fixed formwork, decorative cladding elements, ventilated facades, etc.

Known fiber-reinforced concrete mixture (SU 1201258, VNII on the use of polymeric materials, published 30.12.1985), including Portland cement, sand, fiberglass, liquid polymer composition and water.

A concrete mixture is known (RU 2101248 C1 (Elshina L.I.), published January 10, 1998), including Portland cement, sand, fiberglass, silica fume, a superplasticizer based on the sodium salt of the product of the condensation of naphthalenesulfonic acid with formaldehyde, water and an alkylpolyphenylbenzylide biocide additive.

The closest analogue (prototype) is a fiber-reinforced concrete mixture (EP 0921107 A1 (MCI SA), published on 09.06.1999). The mixture includes cement, sand, rock flour, fine sand, water, polymer fibers, fiberglass, plastic wool and a retention agent.

A common drawback of all these sources is the lack of compressive strength, insufficient tensile and tensile strength in bending, and high permeability of the mixtures.

The technical problem to which the invention is directed is to improve the characteristics of concrete, namely increasing the strength, increasing the compressive strength, increasing the water resistance.

The problem is solved using fiberglass concrete, consisting of a cement-sand matrix reinforced with segments (fibers) of an alkali-resistant (cement-resistant) fiberglass.

More specifically, in one embodiment, in a mixture of fiberglass concrete for use in construction, including cement, a chemical additive, fine-grained sand, roving crumbling from alkali-resistant fiberglass and water, the chemical additive contains, wt.%:

SiO ₂ 88 plasticizer C-3 9-10 water 2-3

alkali-resistant fiberglass has a length of 21 mm to 40 mm, with the following ratio of components, wt.%:

cement 48-53 specified chemical additive 4-6 water 13-17

In another embodiment, in a mixture of fiberglass concrete for use in construction, including cement, a chemical additive, fine-grained sand, alkali-resistant fiberglass fiber and water, the chemical additive contains, wt.%:

SiO ₂ 88 plasticizer C-3 9-10 water 2-3,

and alkali-resistant fiberglass has a length of from 21 mm to 40 mm in the following ratio of components, wt.%:

cement 45-57.5 specified chemical additive 2-8 fine sand 25-35 specified fiber 0.5-9 water 15-20

The cement used is cement grade ПЦ 500 ДО-Н.

The chemical additive contains: SiO ₂ - 88 wt.%, Plasticizer C-3 - 9-10 wt.% And water 2-3 wt.%.

As an alkali-resistant fiber, NEG glass fibers are used.

The mixture is prepared in various ways.

For example, using the method of manufacturing fiberglass concrete by the method of pneumatic spray. The method includes preparing a cement-sand mortar. The solution is prepared by separate weight dosing of cement, chemical additives, sand and water and mixing them in a cyclic concrete mixer. Mixing time 5 min. Then the solution is fed into the discharge unit through a 2 mm sieve. After which the molds must be thoroughly cleaned of the remnants of the fiberglass concrete mixture. The basic linear dimensions of the shapes are checked using tape measure or patterns. A thin even layer of lubricant is applied to the surface of the molds. At the same time, the spray gun is adjusted so that the amount of supplied solution and the amount of chopped fiberglass corresponds to the required composition. At the next stage, pneumatic spraying of fiberglass concrete into the mold is carried out in layers: initially, a preliminary layer of the solution is applied to the mold bottom (without fiberglass 0.5-2.0 mm thick); each subsequent layer (6 mm) (with fiberglass) is applied in two passes in two mutually perpendicular directions; after applying each layer, the mixture is sealed with a spring roller.

Further pneumatic spray and subsequent compaction are carried out until the specified thickness of the product is obtained. After that, the remains of fiberglass concrete are removed from the edges of the mold, the surface of the product is leveled and smoothed. With the help of a bridge crane, pallets with forms are mounted on the stops of storage containers, which are then tightly covered with plastic wrap or any other waterproof material to prevent moisture loss during exposure of the products.

Or, for example, the mixture is prepared using the pre-mixing method. With this method, the process consists of two stages. First, in a high-speed mixer (about 400-700 rpm), a mixture is made by mixing, consisting of cement, sand, water, and a chemical additive. Then, at a lower speed (about 60-75 rpm), an alkali-resistant fiber from 21 mm to 40 mm long is added. When added in very small quantities, the thinnest and highly dispersible fibers are able to inhibit crack opening in concrete at an early plastic stage of its hardening. In combination with the ability of the fibers to inhibit the separation of cement milk, their addition to concrete can significantly improve the properties of hardened concrete. Unlike reinforcing mesh, fiberglass cannot be improperly laid or shifted when laying concrete.

The following are specific examples of various options for mixtures of fiberglass concrete.

Example 1

First, a cement-sand mortar is prepared by separate dosing of 48 kg of cement (PC 500 grade DO-N 48 wt.%), 6 kg of chemical additives (SiO ₂ - 88 wt.%, Plasticizer C-3 - 9-10 wt.% And water 2-3 wt.%, 6 wt.%), 22 kg of sand (22 wt.%), And 17 m ^{3 of} water (17 wt.%) By mixing in a concrete mixer of cyclic action. Mixing time 5 min. Then the solution is fed into the discharge unit through a 2 mm sieve. After which the forms are thoroughly cleaned of the remnants of the fiberglass concrete mixture. Then a thin even layer of lubricant is applied to the surface of the molds. At the same time, the spray gun is adjusted.

At the next stage, pneumatic spraying of fiberglass concrete into the mold is carried out in layers: initially, a preliminary layer of the solution is applied to the mold bottom (without fiberglass 0.5-2.0 mm thick).

Then a subsequent layer (6 mm) is applied together with the roving crumbling from cement-resistant fiberglass with a length of 21 mm to 40 mm in the amount of 7 kg (7 wt.%), In two passes in two mutually perpendicular directions. After that, the mixture is sealed with a spring roller.

The test results for mechanical characteristics are presented in table 1.

Example 2

The mixture is prepared in the same way as in example 1, but with amounts of components equal to: cement 53 kg (grade ПЦ 500 ДО-Н, 53 wt.%), Sand 27 kg (27 wt.%), Water 13 m ³ (13 wt.%), and chemical additives (similar to that described in example 2) 4 kg (4 wt.%). Then, as indicated in Example 1, roving crumbling from cement-resistant fiberglass with a length of 21 mm to 40 mm in an amount of 3 kg (3 wt.%) Is added.

Example 3

First, in a high-speed mixer (speed of 500 rpm) by mixing, a mixture is made of cement of 45 kg (grade PC 500 DO-N, 45 wt.%), Sand 25 kg (25 wt.%), Water 15 m ³ ( 15 wt.%), And a chemical additive (SiO ₂ - 88 wt.%, Plasticizer C-3 - 9-10 wt.% And water 2-3 wt.%) 8 kg (8 wt.%). Then the speed decreases to 75 rpm and an alkali-resistant fiber is added with a length of 21 mm to 40 mm in an amount of 7 kg (7 wt.%).

Example 4

The mixture is prepared in the same way as in example 3, but with equal amounts of components: cement 57.5 kg (grade PC 500 500 DO-N, 57.5 wt.%), Sand 25 kg (25 wt.%), Water 15 m ³ (15 wt.%), And chemical additives (similar to that described in example 3) 2 kg (2 wt.%) And at a speed of 700 rpm. Then the speed is reduced to 60 rpm and an alkali-resistant fiber is added from 21 mm to 40 mm in the amount of 0.5 kg (0.5 wt.%).

Example 5 (prototype).

The mixture is prepared in the same way as in example 4, with amounts of components equal to: cement 39 kg (39 wt.%), Sand 5 kg (5 wt.%), Mountain flour 8 kg (8 wt.%), Fine sand 6 kg (6 wt.%), water 35 m ³ (35 wt.%), polymer fibers 0.5 kg (0.5 wt.%), plastic wool (0.5 kg (0.5 wt.%) and retention agent 5 kg (5 wt.%), and at a speed of 700 rpm, then the speed is reduced to 60 rpm and fiberglass is added from 10 mm to 20 mm in length in an amount of 1 kg (1 wt.%).

As can be seen from table 1, fiberglass concrete has an advantage in mechanical characteristics compared with the prototype. It combines increased compressive strength with increased tensile and tensile bending strength, while the material is not susceptible to corrosion and is non-combustible.

Table 1. Characteristics of the final product. Ave Density, g / cm ³ - in a natural state - of dried concrete - in a water-saturated state Water absorption,% (by weight) Cubic compressive strength, MPa Ground compressive strength, MPA Tensile strength. Pa - in a natural state - in a water-saturated state Bending tensile strength. Pa - in its natural state - water-saturated state Water resistant one 2,213 4.97 66.7 63.3 7.8 23,4 16 2,143 8.47 24.6 2,247 2 2,326 4.63 68,4 65,4 8.0 24.0 fourteen 2,052 8.23 24.2 2,258 3 2,250 4.78 64.5 62.7 7.7 23,2 17 2,247 8.3 24.5 2,251 four 2,216 4.85 65.1 61.8 7.6 23.1 eighteen 2,148 8.15 24.0 2,248 5 1,980 6.01 48.0 49.1 6.1 19.5 25 2,010 7.2 20.1 2,138 Tests were carried out according to GOST 12730, GOST 28570, GOST 24452.

Claims (2)

1. A mixture of fiberglass concrete for use in construction, including cement, a chemical additive, fine-grained sand, roving crumbling from alkali-resistant fiberglass and water, characterized in that the chemical additive contains, wt.%: SiO ₂ 88 plasticizer C-3 9-10 water 2-3 and alkali-resistant fiberglass has a length of 21 to 40 mm, with the following ratio of components, wt.%: cement 48-53 specified chemical additive 4-6 fine sand 20-28 specified roving crumbling 3-7 water 13-17 2. A mixture of fiberglass concrete for use in construction, including cement, a chemical additive, fine-grained sand, alkali-resistant fiberglass fiber and water, characterized in that the chemical additive contains, wt.%: SiO ₂ 88 plasticizer C-3 9-10 water 2-3 and alkali-resistant fiberglass has a length of 21 to 40 mm, with the following ratio of components, wt.%: cement 45-57.5 specified chemical additive 2-8 fine sand 25-35 specified fiber 0.5-9 water 15-20