CS243924B1 - Anchoring layer to increase the adhesion of diesel blends to smooth substrates - Google Patents

Abstract

Anchoring layer intended for increasing the adhesion of surface treatments with mortar mixtures to smooth substrates of structural elements of building objects, characterized in that it consists of a mortar mixture (silicate or plastosilicate) and asphalt suspension or emulsion modified with synthetic rubber, the amount of which does not exceed 5% of the weight of the mortar. The invention applies to steel structures.

Description

243924

The present invention provides an anchor layer for increasing the adhesion of mortar mixtures to the smooth construction of structural elements. In practice, it is often the case that lime, lime-cement and fire-resistant plasters are required to be applied to smooth concrete, steel and other surfaces that do not guarantee perfect coherence with the substrate and the cause of frequent defects due to their loosening. Better results are obtained when the treated surface is provided with rabitz-ram or other mesh. Such adjustments are common, for example, in the application of steel profiles, steel profiles, whether for fire protection or for the application of traditional omissions. Often there is a problem of fire protection of trapezoidal sheets, where fastening the mesh is almost impossible. Some render compositions are known to increase the adhesion to the substrate, prepared on the basis of aqueous dispersions of synthetic resins in the form of thin-film plasters, intended for smooth and straight concrete concretes, optionally porous. They do not have good adhesion to steel profiles and sheets and cannot be applied in thicker layers. In addition, the vogue is acidic, increasing its corrosive effect.

Some techniques of applying fire-resistant plasters suggest that prior to the actual treatment, the anchorage coatings must be applied, which must not dry out so that the elastic protection is bonded.

The aforementioned drawbacks are eliminated by the anchor layer according to the invention, prepared in the presence of a thin mortar from the same plaster mixture used to modify the structural element, with the addition of a water-soluble asphalt suspension, but emulsified with synthetic rubber. Drying after 4 to 24 hours (depending on substrate suction and air temperature), the formed anchor layer with granular structure is well bonded to the actual surface treatment. The adhesion of the thus realized coating exceeds the required value, and is generally higher than its cohesion. Furthermore, when applied to steel constructions, mainly for fixing fire-resistant plasters, it eliminates, for example, the corrosion-inhibiting effect, in the case of plaster or dispersion mixtures. Another advantage of the anchoring layer is the flexible connection of the substrate to the plaster layer, which is effective for different volume changes, e.g. metal constructions! with a fire-resistant plaster prepared on the basis of silicate binders.

The anchor layer according to the invention consists of a conventional cementitious, cement-lime, gypsum or plastosilicate plaster mixture with the addition of a water-dilutable asphalt suspension or a synthetic rubber modified emulsion. The amount of suspension or emulsion expressed in the rubber content of the co-layer should not exceed 5% by weight of the mortar. The viscosity is modified with water, depending on the coating in such an amount as to form a granular anchor layer with the most abundant surface, for perfect bonding by its own surface treatment. Example 1

According to this example, the anchoring layer prepared from the PYROTHERM fire-resistant plaster mixture has the following composition: - 60 1 mortar 57.6 kg - 4 kg asphaltlate suspension SA — 10 4.0 kg - water 5.0 kg

The anchoring layer was sprayed on the steel canvas pistol with a smooth gun. A custom fire-resistant plaster of about 1.5 cm thickness was applied for 24 hours. After 28 days of hardening, the substrate holding value measured according to CSN 73 2577 was 0.42 MPa, with a rupture of the sample. Example 2 According to this example, the anchoring layer prepared from cement-lime mortar has the following composition: - 1 000 1 sand - 150 kg cement SPC 325 - 50 kg lime hydrate - 60 1 water - 100 kg asphaltlate suspension SA — 10

The anchoring layer was sprayed in the same manner as in Example 1, with a subsequent layer of lime-cement plaster, at a thickness of about 1 cm on a steel U-profile, serving as an inoculated lintel, impregnated by crushed mesh. After 28 days of hardening, the cohesion with the substrate measured according to ČSN 73 2577 was equal to 0.38 MPa.

The standard criterion prescribes a bond strength of 0.2 MPa for interior finishes. The lime-cement mortar applied to the steel profile without anchoring layer achieves a adhesion of 0.05 to 0.11 MPa.

Claims (1)

An anchor layer for increasing the adherence of mortar mixtures to smooth substrates of building elements, characterized in that it consists of a mortar mixture of a silicate or plastosilicate and, in the invention, a thinned asphalt slurry or an emulsion modified with a synthetic rubber of less than 5% by weight.