CS263295B1 - Building material with increased abrasion resistance - Google Patents

Abstract

The construction material with increased abrasion resistance and high strength uses quartz grains covered with a layer of crystalline silicon carbide, diffusely bonded to the quartz grain. The increased specific surface of the quartz grains treated in this way ensures, in addition to increased abrasion resistance, increased cohesion of the grain with the binder and thus increased strength of the surface treatment. The construction material is suitable for creating high-strength tread and travel layers with high resistance to abrasion, both in factory halls, warehouses and on ramps, as well as in road and railway construction. The construction material can be used not only in outpatient applications, but also in prefabrication. The description provides several examples with inorganic and/or organic binders. These examples are far from exhausting the application possibilities of the material.

Description

The invention relates to a building material with increased abrasion resistance intended for surface treatment of building structures, prepared mainly as a dry prefabricated material with inorganic and/or organic binders.

There are many known ways to increase the surface strength of building structures and their abrasion resistance. They consist mainly in spreading abrasion-resistant materials such as steel shot, cast iron grit, crushed artificial corundum or sintered corundum, silicon carbide, crushed quartz or sand onto the worn surface of a concrete structure, or enriched with the addition of a binder for floors, etc. On a global scale, there are also manufacturers of prefabricated, dry materials that are applied to the worn surface of a concrete base. In the vast majority, these materials are made of an inorganic binder and mixtures of the aforementioned abrasion-resistant fillers of various granulometry. There are also materials bonded with resin binders, prepared mainly on an outpatient basis from a mixture of quartz sand with abrasion-resistant particles, e.g. artificial corundum or silicon carbide, with a large variability in the mutual ratio.

The disadvantage of these materials is that their cohesion is determined only by the adhesion of the binder to the abrasion-resistant filler with a relatively small specific surface of the filler, formed by smooth contact surfaces in the case of crushed stone or smooth spherical surfaces of quartz sand grains. Their strength and abrasion resistance are directly proportional to the adhesion of the abrasion-resistant grain to the binder mastic. The specific surface of these fillers is determined by their origin, whether manufactured (crushed filler) or natural (quartz sand). Similarly, the specific surface of the filler grain also affects the strength of the building material, especially in tension and bending.

These disadvantages are eliminated by the building material according to the invention, which contains 4 to 96% by weight of quartz grains, the surface of which is formed by 7 to 31% by weight of crystalline silicon carbide, diffusely connected to the quartz grain.

The building material may contain additional abrasion-resistant fillers such as artificial corundum, silicon carbide, quartz, cast iron grit or steel shot, as well as additives affecting the mechanical-physical and technological properties of the material, such as plasticizers and flow agents, retention additives, binder setting retarders or accelerators, setting catalysts, flow and defoaming agents, additives and admixtures increasing adhesion to the substrate and cohesion of the material.

The building material according to the invention has an indisputable advantage, which lies in the fact that crystalline silicon carbide, formed during the electrothermal reaction of silicon dioxide (quartz sand) with carbon, increases the specific surface area of the quartz grain and thereby increases its cohesion with the binder, in addition to the adhesive forces, also by mechanical anchoring of the binder in the surface of the grain. In addition, silicon carbide, diffusely bonded to the quartz grain, increases the abrasion resistance of the quartz grain.

For this reason, the cohesion of the building material formulated in this way is significantly higher, which results not only in increased strength of the material, but also in increased resistance of the abrasion-resistant grains against release from the binder bed.

Specific composition and use of building materials in examples that are far from exhaustive according to the invention, it is demonstrated in several areas of application. Example 1 A dry prefabricated mass was prepared about this composition. Quartz grains with Sic surface (0.25/3.15 mm) 4.4% wt. Quartz sand (1.6 /3.15 mm) 35.5 » wt. Cast iron scrap (0.25/3.15 mm) 17.8% wt. Sintered corundum grit (0.25/3.15 mm) 15.6% wt. Brown corundum (0, /0.5 mm) 4.8% wt. PC 400 20.1% by weight

Liquid (dry matter) Retention agent

1.4% by weight 0.5% by weight

and spread onto the surface of the floor concrete of class B 35 shortly after the concrete began to set in a thickness of approximately 4 mm and rubbed into the substrate with a vibrating screed. The samples taken for testing showed the following properties:

Days: 7 14 28 Volumetric weight kg.m ^-3 2,843 2,824 2.7 Bending tensile strength MPa 3.7 6.9 10.7 Compressive strength MPa 32.6 43.3 80.2 3-2 Abrasion (Bohm) cm.50 cm - 7.7 5.7

Example 2

A dry prefabricated mass was prepared and processed using the technology described in Example 1. The mass had the following composition:

Silicone grains with SiC surface (0.25/3.15mm) (1.6/3.15mm) 21.2% by weight 18.8% by weight FP quartz sand 6 Cast iron handle (0.25/3.15mm) 2.2% by weight Sintered corundum (0 /3.15mm) 2.7% by weight Brown corundum (0 /3.15mm) 28.4% by weight Corundum dust (under 0.09 mm) 5.1% by weight PC 400 18.5% by weight Runaway 1.5% by weight Retention additive 0.5% by weight Redispersible dry dispersion 1.3% by weight

Samples taken from the mass showed the following properties:

Days -3 Density kg.m 7 2,734 14 2,695 28 2,614 4 Bending tensile strength PMa 7.1 13.7 16.1 Strength in talc MPa 42.3 66.7 92.6 3 -2 Abrasion (Bohm) cm .50 cm - 5.2 3.1

In addition, a reference sample was prepared in which quartz grains with SiC surface were replaced by quartz grains without this surface (sand FP 6) and processed in the same way. The samples taken showed the following properties:

Days 7 14 28 Volumetric weight kg.m" ³ 2,701 2,662 2.5 Bending tensile strength MPa 5.6 8.9 10.3 Compressive strength MPa 30.1 55.4 79.4 3-2 Abrasion (Bohm) cm .50 cm - 7.2 5.9

Example 3

A 12 mm thick concrete layer was made on a concrete base made of B 35 in the hall of an industrial plant with very heavy traffic, using the following composition:

Quartz grains with SiC surface, special granulometry 0/4 95.85% by weight.

Low molecular weight epoxy binder including flow-through and defoaming agent

4.15 tons of mass

At the same time as the TLM, a reference mass was prepared only from quartz sands of the same granulometry and the same binder. The samples obtained showed the following properties after complete curing and thermal curing for 24 h/20 °C and 72 h/80 °C:

Mass KP-SiC KP Bending tensile strength MPa 23.1 16.1 Compressive strength MPa. 67.6 53.3 Abrasion (Bfihm) cm ³ .50 cm ² 1.3 2.7

Example 4

For the surface treatment of the floor in a warehouse with forklift traffic, a prefabricated dry casting compound with increased abrasion resistance of the following composition was prepared:

•Her

Quartz, grains with SiC surface (0/3.15 mm), 22.0 » wt.

Brown corundum firing (0/3.15 mm) 19.1 ΐ wt.

Limestone crushed stone (/1 mm) 36.9% by weight.

PC 475 18.9% wt.

Complex additive according to Czechoslovak AO 263 289 3.1% by weight.

and mixed on site with a reactive styrene-acrylate copolymer dispersion diluted with water in a ratio of 1:9 to a thick liquid consistency and applied to a moistened concrete substrate in an average thickness of 6 mm, where it created a surface. After 28 days/18 °C, the surface treatment had the following properties:

Adhesion to the substrate MPa 1.05+0.23

Bending tensile strength MPa 9.4 + 1.06 Compressive strength Mpa 42.3 + 2.1 3-2 Abrasion (Bohm) cm .50 cm 4.6 + 0.3

Example 5

A liquid compound consisting of 72 parts by weight of solids and 28 parts by weight of water was prepared on site and applied to the moistened concrete base of the warehouse. The self-leveling compound created a level. The dry proportion of the compound had the following composition:

Fluorspar ground to 0.2 mm

Quartz, grains with SiC surface (0.0/1.6 mm)

Brown corundum firing (0/1)

Complex additive according to Czechoslovak AO 263 289

After 28 days, this surface treatment had the following properties:

: to the base MPa 0.73 + 0.18 bending tensile MPa 10.2 + 1.32 pressure MPa 33.1. + 2.27 (Bohm) cm ³ .50 ^cm 6.26 + 0.24

Replacing quartz grains with SiC surface with quartz sand of the same abrasiveness by 17.6 t.

56 4 mass 28 % mass 11 % mass 5 « mass

granulometry increased

The building material according to the invention can be advantageously used in the production of highly strong and abrasion-resistant walking and driving layers both on-site and in the prefabrication of building elements, e.g. staircases, flat road and rail prefabricates, and the like.

Claims (4)

CLAIMS 1. An abrasion-resistant building material bonded with inorganic and / or organic binders, characterized in that it contains 4 to 96% by weight of quartz grains with a surface consisting of crystalline silicon carbide diffusively bonded to the quartz grain, wherein crystalline silicon carbide constitutes 7 to 31%. by weight of the weight of the grains. 2. Building material according to claim 1, characterized in that it contains abrasion-resistant fillers, such as artificial corundum, silicon carbide, quartz, steel or / and cast iron grit. 3. Building material according to claim 1, characterized in that it contains dyes and pigments. 4. Building material according to claim 1, characterized in that it contains additives affecting the mechanical-physical and technological properties of the material.