CS268431B1 - Silicate material for thin film coating - Google Patents

Abstract

Silicate mass for creating thin-layer surface treatments, especially floor coatings in residential, civil and industrial buildings in thicknesses from 0 to 25 mm, consisting of cement binder, ground limestone or other mineral crushed materials with a grain size of maximum 4 mm, containing 0.5 to 2.4 % by weight of swelling wheat starch. To improve properties, plasticizers, pigment additives and aqueous dispersion of macromolecular substances can be added.

Description

The invention relates to a silicate composition for forming thin-layer treatments, in particular floors of residential, civil and industrial buildings in thicknesses from 0 to 2 mm.

Thin-layer floor finishes in small thicknesses in the so-called zero modulus are based on materials based on silicate binders and it is very problematic to create surface finishes in the floor structure in thicknesses that are small but greater than 3 mm. When used in these cases, due to their large volume changes (fillers with a small grain size), their frequent defects, ie flaking, cracking, dusting of their surface, or destruction of the entire layer. Apart from the fact that if they are to compensate for only minimal surface irregularities - grooves for electrical conductors, joints · and the like, they are unusable in such cases for the reasons stated above. We must not forget the fact that the modifying additives that the substances contain make them very expensive.

The mentioned cases are not solved by the casting floor systems used in our country, which are not suitable for thin-layer floor treatments due to their small thicknesses of floor layers.

These disadvantages are eliminated by the dry silicate composition according to the invention, which consists of a dry mixture of homogenized limestone or other mineral grit, cement and special additives mixed in water, to which liquefying additives and other modifying additives can be added.

Its essence lies in the fact that the dry mixture, consisting of cement binder, ground limestone or other mineral crumbs with a grain size of at most 4 mm, further contains 0.5 to 2.4% by weight of swellable, for example wheat starch.

The dry mixture can be further treated with 0.8 to 3.0% by weight of inorganic pigment additives. When mixed in water, the resulting system can be adjusted by adding 0.3 to 24 wt. or PVAC with a dry matter content of 50 to 55 4 by weight. ⁴

The composition according to the invention has a number of advantages, the most important of which is that its composition is very simple, without the need for expensive additives. After mixing with water and the flowing additive, a stable silicate mixture is formed which is easy to pour, in which the individual phases do not settle.

The optimal ratio of fillers, binders and modifying additives ensures the achievement of very good final mechanical and physical parameters. Appropriately selected dose of swellable starch allows in the actual process of solidification and hardening controlled control of hydration processes, and thus ensures a quality course of hydration in small layer thicknesses, and thus favorably limits the size of volume changes. In practice, this means removing cracks in these thicknesses, increasing the strength parameters and strengthening the actual surface of the layers.

The resulting silicate mass is preferably used for the formation of thin-layer floor layers of the base or final, or for the repair of the bases of floor constructions, or it can also be used for other surface treatments. Its use assumes that the construction readiness is at the same level as usual before the implementation of conventional base concretes. The dry silicate mass can be prepared in the dry state in a special factory or in the production of dry plasters, while water, liquefying additives and other liquid additives are mixed with it only on the construction site. The mixture can be processed in common types of machine mixers with mixing and pumping equipment. The created liquid or soft mixture can be transported with rubber hoses to a distance and height of several tens of meters. The layer is applied as needed, usually from virtually zero thickness to 30 mm thick.

Surface finishes can be created by pouring or in the traditional manual way, ie by smoothing.

The specific composition of the silicate mass is further illustrated in the following examples:

Example 1

It was predetermined that the base floor layer in the assembled building will have a height of 10 mm, with the thickness of the layer reaching 25 mm in the places of the grooves for electrical installation.

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In the mixer of the plasterer, a mass was prepared with the composition: Dry silicate mixture 55> t by weight water 44.5% by weight flowing additive of sulfone type 0.5 S by weight

The dry silicate mixture was composed of the following components:

Portland slag cement SPC class 325 49% by weight ground limestone, grain size 0 to 1 mm 50% by weight swelling wheat starch 1% by weight

After mixing, the mixture was pumped by a two-piston mortar pump into the individual floors of the building and poured to a pre-marked height on the walls of the rooms.

After 28 days of aging, the hardened subfloor was subjected to measurements of decisive mechanical and physical parameters, which reached the following values: compressive strength according to ČSN 74 4505 20.5 MPa flexural tensile strength according to ČSN 74 4505 5.9 MPa volume stability according to ČSN 73 1320 ( after 90 days) 0.41% ·

On the same floor of the prefabricated building in two rooms, a cement screed was originally made of the composition: fine aggregate 0 to 4 mm 60% by weight slag-Portland cement SPC 325 24% by weight water 16% by weight

The floor after hardening was dusty.

The cement screed sample showed numerous volume radial cracks, the surface was subjected to the following tests with the results:

compressive strength according to ČSN 74 4505 flexural tensile strength according to ČSN 74 4505 volume stability according to ČSN 73 1320 (after 90 days)

21.8 MPa

4.1 MPa 0.078

After these results, it was decided to use a silicate mixture suitable for forming thin-layer coatings.

Example 2

The asphalt-concrete surface of the storage areas of the civic amenity facility had innumerable defects, mainly of the nature of potholes, volume cracks and potholes, with a maximum depth of 10 mm.

The floor in the stated condition was intended for reconstruction, consisting in pouring the floor layer to a height of 10 mm.

Prior to the actual application of the final layer, the base surface was impregnated with a reinforcing varnish based on water-soluble epoxy resins. After production in a plaster mixer, a mass of the following composition was poured on the substrate thus prepared: dry silicate mixture 54 A by weight water 46% by weight

The dry silicate mixture, which was transported to the construction site in paper bag packaging, had the following composition:

Portland cement PC 400 45 \ by weight ground limestone, grain size 0 to 1 mm 51,5 ¾ by weight swelling wheat starch. 1.5% by weight

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A sample of the final tread floor was subjected to measurements of its mechanical and physical parameters:

flexural tensile strength according to ČSN 74 4505 6.1 MPa compressive strength according to ČSN 74 4505 25.3 MPa volume stability according to ČSN 73 1320 (after 90 days) 0.042 ¾.

Claims (2)

OBJECT OF THE INVENTION A silicate composition for forming thin-layer coatings, comprising a cementitious binder, ground limestone or other mineral crumbs with a grain size of at most 4 mm, characterized in that it further comprises 0.5 to 2.4% by weight of wheat swelling starch. 2. The silicate composition according to item 1, characterized in that it further contains 0.8 to 3% by weight of inorganic pigmenting additives, 0.3 to 2% by weight of liquefying additives of the phenolic or sulfone type or 0.5 to 10% by weight of aqueous dispersions of macromolecular substances of the starene-acrylate or PVAC type and 50 to 55% by weight of dry matter.