CS229806B1 - Multi-purpose building material - Google Patents

Description

The invention relates to a multipurpose building material which can be used in particular for bonding plasters carried out at lower temperatures.

At present, the production of prefabricated bonding plasters is solved by the fact that suitable moisturizing binders are pre-fabricated with fillers and retention. additives based on water-soluble cellulose ethers. In the case of gypsum binders, the solidification and hardening agents of the gypsum binder are based on weak organic and inorganic acids and their salts, and in the case of anhydrite binders, solidification catalysts of different compositions. In the case of cement and lime binders, these are known additives such as aluminous cement or aluminous cement. gypsum, which expands the shrinkage of the mass during hydration. For some products, the use of low-temperature additions of various alkaline or amifotenic acid salts is suggested to accelerate the hydration reaction and reduce the freezing point of the water.

This technology has not resolved the blooming of salts added to provide a hydration reaction at reduced temperatures or to regulate hydration at normal temperatures. as solidification and hardening catalysts for anhydrite building materials or for retarding solidification in gypsum building materials.

Likewise, the decrease in strength and adhesion of wet calcium sulfate and lime-based building materials containing water-soluble additives to water retention and increased adhesion to the substrate remains unresolved. These drawbacks are largely solved by increasing the strength class of the hydrating binder or by increasing the pressure when applying building material to the substrate or by forming bonding bridges to increase the adhesion of the building material to the substrate.

The above-mentioned disadvantages are substantially eliminated by the multipurpose building material according to the invention, which consists in that it consists of 100 wt. parts of inorganic moisturizing binder, 0.002 to 15 wt.%, parts of dry weight of plasticizing additive, 0.001 to 10 wt. parts of urea, 0.001 to 10 wt. and 10 to 200 wt. parts of water.

It is preferred that one of the following materials be used as the inorganic hydration binder: anhydrite, cement, gypsum or lime, or mixtures thereof.

It is further preferred that sulfonated poly- or copolycondensate of substances containing at least two -NH ₂ groups in the molecule with formaldehyde or its homologues, e.g.

229808 Sulfonated polycyclic urea condensate with formaldehyde or its homologues.

It is preferred that cellulose ethers containing free -OH groups are used as retention aids.

The building material according to the invention may contain dispersions of organic resin polymers containing free OH groups.

The building material according to the invention may also contain a filler.

The advantages of the building material according to the invention consist in particular in that the additive-containing sulfonated plastififeační _-NH2 group reacts with simultaneous crosslinking with the free -OH groups retention aids inebo free -OH groups in dispersions of organic polymers and copolymers and their sulfo iopty reacts with alkaline earth metal, e.g. % of calcium, to form insoluble addition of urea (%) salts, eg calcium, of the resulting reaction product. The effect of the urea according to the invention is that rapid formation of amorphous precipitates of insoluble salts does not occur in the presence of urea, but rather slow formation of crystalline products, which affects the positively ultimate mechanical strength and adhesion of the building material to the substrate. This also positively affects the so-called wet strength of the building material. The slow formation of crystalline products extends the pot life by blocking false solidification resulting from the use of sulfo group-containing additives.

This effect is best shown in the table of the effect of urea addition in the plaster prepared according to Example 2.

, 0 0.5 1 2 4 • Start of solidification [min.] 60

End of setting (min.) 110

The composition of the invention is illustrated by the following examples.

He did

90 105 115

110 112 115 133 can not work on the final strength of the hardened material.

Example 1 a d 2

Liquid leveling screed Conhydrite, prepared according to AO 204 076 with a composition of 100 wt. 0.2 parts by weight of anhydrite; parts of potassium sulfate and 1.3 wt. parts of sodium sulfate as the solidification and hardening catalyst were mixed in a 0.5 wt. parts of expanded perlite, 1.0 wt. parts of urea, 0.2 wt. parts of hydroxyeityl cellulose and 650 wt. parts of barite sand with a grain size of 0 to 7 mm. The thus prepared dry mixture was metered into a forced mixer in which it was previously dissolved in 60 wt. parts of water 0.5 wt. parts by weight of Umaform SM (sulfonated amino-s-triazine sulfonated polycondensate with formaldehyde) and 1.3 wt. parts by weight of sulfonated urea polycondensate with formaldehyde and 0.1 wt. parts alkaline-. salts of polyacrylic acid.

The mixture prepared in this way was poured onto the floor of the X-ray workplace of the polyclinic in thickness. 2.5 cm. From this building material, a cladding for a flat flooring with a flat and smooth surface was created by stretching, sufficiently shielding the passage of X-rays through the floor. This washer exhibited, after seven days, the mechanical-physical properties achieved with conventional screeds usually after 28 days, i.e. an approximate compressive strength of 28 MPa, which cannot be achieved with screeds of this class of classical materials.

Building material of the same composition was otherwise tested in the building at a construction temperature of –7.3 ° C and an air temperature of –10.4 ° C. The solidification and hardening of this material was slower, but without the effect of low temperature (at which, with a conventional cement screed or barite screed with cemen 100 parts by weight of cobbler gypsum, it was pre-mixed with 30 parts by weight of lime, 350 parts by weight of barite sand). 0 to 2 mm and 50 parts by weight of the functional additive consisting of 2.5 parts by weight of the dry matter of sulfonated urea polycondensate with formaldehyde of molecular weight greater than 20,000, 2 parts by weight of urea, 0.4 parts by weight of carboxymethylcellulose (Lovosa TS 20) and 0.05 parts by weight of polyacrylamide as a retention additive, 0.05 parts by weight of tartaric acid as a gypsum retarder pre-ground with 45 parts by weight of barite flour, which was mixed in a continuous mixer, transport and sprayer with 166 parts. parts by weight of water and sprayed in a layer of 3.5 cm onto the siporex partitions X-ray of the polyclinic workplace at the construction temperature —2 5 ° C and an ambient temperature of -5.8 ° C. The plaster was leveled with screeds, after hardening it was smoothed with a plaster coated with a polyurethane sponge soaked in water until a plaster was formed and then smoothed with a steel trowel.

The plaster thus formed exhibited a compressive strength of more than 3 MPa after five days, which is not achievable under the conditions of a barite plaster with a conventional binder.

Example 3 wt. parts of cobra building gypsum were premixed with 20 wt. parts of lime hydrate, 125 wt. parts by weight of fine sand with a grain size of 0 to 0.15 mm, 2 wt. parts of expanded perlite having a particle size of up to 0.5 mm and 30 wt. parts of functional additive, se229806

With an existing of 1.5 hmoit. parts by weight of salified urea polycondensate with formaldehyde, 0.7 wt. 0.1 parts by weight of urea, 0.15 polyacrylic acid sodium salt, 0.2 wt. parts by weight of water-soluble carboxymethylcellulose, 0.35 wt. parts of water-soluble acetylcellulose and 0.1 wt. parts of sodium citrate as a gypsum solidification retarder pre-ground with 27 wt. parts of powdered limestone.

This prefabricated dry mixture was mixed in a continuous mixer, transport and cutting machine with 75 wt. parts of water and sprayed on the ceiling formed by reinforced concrete ceiling in a layer of variable thickness. 2 to 25 mm, depending on the unevenness of the precast elements and the joint depth. After solidification, the sprayed layer was smoothed with a wet felt trowel, and after the plaster was pulled to the surface, it was run over with a sponge roller which formed a linkrust structure on the plaster ceiling layer.

The thin-layer leveling plaster thus formed in a single-layer construction achieved its performance after 48 hours, its adhesion on the smooth surface of the ceiling prefabricated component being higher than 0.4 MPa,

Example 4

By mixing 60 wt. parts of cobbled building gypsum, 20 wt. parts of high-strength plaster DHG, 10.5 wt. parts of lime hydrate and 20 wt. parts of expanded perlite EP 150 with 30 wt. parts of the functional additive prepared in advance by grinding 1.5 wt. % of sulfonated urea polycondensate with formaldehyde, 0.45 wt. parts by weight of water-soluble hydroxyethylcedulose, 1 wt. % urea and 0.05 wt. 27 parts by weight of sodium tartrate as a solidification retardant. parts of the powdered gypsum were made with a prefabricated dry mixture which was mixed with 135 wt. parts of water and sprayed on partitions made of precast concrete in the corridors and staircases of residential buildings in the thickness. 3 cm. After comparison in the manner described in Example 3, a spruce roller was formed by limbrust design.

After three days the prepared plaster at functional temperature +15 ° C and air temperature +20 ° C had functional properties, ie specific density less than 460 kg / m ³ , specific thermal conductivity less than 0.1 W / m ° K and a compressive strength greater than 1.0 MPa, thereby achieving the required thermal insulation of the living rooms adjacent to the unheated corridors and staircases.

Example 5

100 wt. parts of stucco gypsum SG 5 were premixed with 150 wt. parts of dredged sand with a grain size of 0 to 0.6 mm, 10 wt., parts of expanded perlite EP 100 and 30 wt. parts of a functional additive comprising

0.75 wt. parts by weight of methylhydroxyethylcellulose, 1.25 wt. parts by weight of sulfonated urea-formaldehyde resin, 0.7 wt. 0.3 parts by weight of urea parts by weight of sodium phosphate solidification retarder, pre-ground with 27 wt. plaster parts. The prefabricated powdered building material was mixed in a forced mixer with 215 wt. 4 mm and a depth of approx. 12 cm between the window frames and the window opening resulting from the folding of the building envelope elements. By hydrating the expansion of the building material, the window frames were perfectly sealed in the window opening. After three hours, the building material had a compressive strength of 4.5 MPa. After seven days, the building material had the following characteristics:

Specific gravity 1060 kg / m ³

Specific thermal conductivity 0.55 W / m ° K

Compressive strength 9.8 MPa.

Bending tensile strength 2.3 MPa

Linear Hydration Change +0.015%

These properties do not reach the classical building materials.

Example 1 a d 6

P. for winter concreting of exposed concretes was prepared in bet. concrete mixer with a composition of 330 wt. parts of dispersion cement PC 400, 950 wt. gravel sand 0 to 8 mm, 380 wt. Crushed aggregates 0 to 16 mm, 770 wt. parts of crushed aggregate 16 to 22 mm, 150 wt. parts of water in which 3.5 wt. 3 parts by weight of sulfonated urea polycondensate with formaldehyde; parts of urea and 16.5 wt. parts of soda (Na ₂ CO ₃ ) as antifreeze and 0.75 wt. parts of carboxyethylcellulose.

This concrete mix had an Abrams cone settlement of 17 cm. After hardening and de-molding, no efflorescence appeared on B250 exposed concrete in 2 years. The actual cubic strength achieved was one class higher, ie Rb23 = 37.8 MPa.

Example 1 a d 7

Into the mixing water reduced by 12% for a concrete mixture intended for concreting of piles in an aggressive environment, 1 wt. % of sulfonated polycondensate of amino-s-triasine (had to be mixed with formaldehyde, 2.5% by weight of sulfonated polycondensate of urea with formaddehyde, 0.3% by weight of urea and 0.15% by weight of polyacrylic acid sodium salt. consistency, did not wash out when poured into water, and the individual doses were well combined from the water.

The hardened concrete had a 10% higher bulk density, a 45% higher compressive strength, a closed surface compared to a concrete of the same consistency prepared without additives. Changes in the mechanical-physical properties in the environment of aggressive water with a tenfold concentration of aggressive substances were not observed in the prepared material even after 2000 din. For comparative concrete the changes were apparent after 210 days and after 2000 days this concrete was completely disintegrated.

Example 8

Concrete pool with small cracks and insufficient waterproofing of concrete was repaired with lime-cement plaster thickness. 1.5 cm of the following composition:

350 wt. parts of cement PC 400, 80 wt. parts of hydraulic lime, 1600 wt. parts by weight of river sand with a particle size of 0 to 2 mm; parts of bentonite and 10 wt. parts of aluminous cement to suppress shrinkage of mortar with 1 wt. part of carboxymethylcellulose was premixed and introduced into a high-speed forced mixer in which 160 wt. parts of water, 8 wt. 3 parts by weight of sulfonic polycondensate of urea with formaldehyde; parts of urea, 5 wt. parts by weight of sodium carbonate, 17 wt. 0.5 parts by weight of a styrene acrylate dispersion copolymer; parts of potassium soap.

The resulting mortar was mechanically sprayed under a pressure of more than 0.7 MPa on the cleaned and rinsed wall of the pool. After leveling and setting, the plaster was smoothed first with a felt and then with a steel trowel.

There were no efflorescence on the plaster for three years or water leaks from the plaster.

The advantage of the proposed multipurpose building material is its wide application in the construction industry in conditions where other materials cannot be used without special measures.

The materials can be used as plasters for both manual and machine application. It is possible to make single-layer plasters from the thickness of approx. 1 mm to 55 mm, as heat, sound, or waterproofing, or increasing the fire resistance of the plastered construction or shielding against radiation. In a lightweight design it reduces the wicking of moisture in the masonry. The materials can also be used for gluing tiles or joints.

The mass can also be applied as floor mats with a soundproofing or shielding effect against radiation. For its adhesion, the mass can advantageously be used for thin-layer and smoothing screeds.

The proposed material can be used for concreting structures that are exposed to an aggressive environment. It also makes it possible to carry out concreting opd with water as it does not wash out and the individual batches are well connected under water.

The mass can also be used for creating exposed concrete.

This multipurpose mass can be prepared for underwater concretes, as it does not wash off the mix, or it can be prepared preferably at the factory and delivered to the construction site.

The invention can be used in civil engineering for the realization of civil, industrial and residential buildings. It will also find application in the implementation of special buildings, engineering structures and waterworks.

Claims (5)

přomE: Multi-purpose building material, characterized in that it consists of 100 parts by weight of an inorganic hydrating binder, 0.002 to 15 parts by weight of the NH ₂ plasticizing additive dry matter, 0.001 to ^Λ 10 parts by weight of urea, 0.001 to dílů0 parts by weight of a retention additive free OH groups and 10 to 200 parts by weight of water. Multifunctional building material according to claim 1, characterized in that the plasticizing additive containing at least two NH ₂ groups is a water-soluble sulphated urea polycondensate with formaldehyde and its homologues up to C 20, or a mixture of sulphonated urea polycondensate with formaldehyde HYDRO and its homologues. up to C 20 with commercial plasticizers and fillers. Multifunctional building material according to rolls 1 and 2, characterized in that the retention additive is a cellulose ether containing free OH groups or polyacrylamide, or an alkali or ammonium salt of polyacrylic acid, or a mixture of at least two of said additives, Multifunctional building material according to Claims 1 to 3, characterized in that it contains aqueous dispersions of polymeric resins with free hydroxyl groups. Multifunctional building material according to Claims 1 to 4, characterized in that it contains a filler.