CS248791B1 - The method of impregnation - Google Patents

Abstract

The solution concerns impregnation and insulation materials intended for construction. The purpose of the invention is a new method of impregnation or insulation preventing the penetration of water and aqueous solutions through concrete surfaces. The stated purpose is achieved by the gradual application of reactive compositions of various compositions with various target properties based on new tough epoxies, which are characterized by excellent adhesion, resistance to wear, weathering and temperature changes.

Description

The invention relates to a method of impregnating or insulating, preventing water and aqueous solutions from penetrating the concrete surfaces of tanks, pools, reservoirs, sewers and the like.

)

Our country does not have large reserves of water. That is why we must manage it well, protect our drinking water resources. Especially in such areas as the South Moravian Region. Long-term watertightness is required not only for sanitary water structures, such as reservoirs, storage tanks, sewage treatment plants and the like, but also for ground tanks, silage pits, swimming pools, digesters, sludge pits and the like.

.Combined chemical influences can affect the hardened concrete, either by attacking water, by the action of gases and air, by soil and soil minerals, or by chemicals. Rotating water attacks concrete most often. In addition to the concentration of the aggressive components contained in it, its amount is also important. Rotating water disrupts the concrete by disrupting and leaching the components of the cement, forming new, less solid compounds, or forming insoluble compounds that increase their volume and expand the concrete by expansion. The assault waters are hungry, acid, carbonic, sulphate and chloride waters.

At first there was an effort to produce waterproof cement plasters. However, their quality depends too much on the quality of the design, since otherwise it often bursts, becomes permeable and requires expensive repairs. Progress was achieved by machine plastering and the use of colloid mortar. However, the results were not satisfactory, and even sealants such as calcium and alkaline soaps did not provide a solution to the problem, since they only sealed the micropores in the binder, which must themselves be dense and impermeable. In most cases, sealants reduce the mechanical strength of both mortars and concretes, so they cannot be used with new concretes and in some environments, concretes with admixtures will break down earlier than without admixtures.

That is why bituminous insulation systems have been used for many years. They are an integral part of the building structure and consist of various primers, asphalt sealants, hot applied, or a series of superimposed reinforcing inserts, joined by asphalt coatings and the like. However, at decreasing temperatures they become brittle and lose their adaptability to the deformations of the substrate. Rheological properties, in turn, limit their use to a certain temperature range. It is the cause of many failures.

Asphalt bitumens are better than tar bitumen. In cold weather there is a risk of premature solidification of the resins and thus their poor spreading. If the temperature of the base masonry is lower than +5 ° C, the masonry must be heated, otherwise the cracks in the coating would be rendered worthless. The frost coating is brittle and slightly damaged. Another disadvantage of resins is that they have a constant plastic flow.

Recently, plastics have been increasingly used in the Czech Republic and abroad. These are, for example, polyvinyl chloride films. Their disadvantage is the difficult and often imperfect connection (by gluing, hot air and high frequency heating) and then that the water extracts from the plasticizer films, hardens, bursts, loses elasticity and leaks. Therefore, they are only suitable as intermediate insulation. Joining metal strips is even more difficult. The use of silicones encounters considerable shrinkage. Conventional epoxy resins have low ductility and cracking during concrete deformation. Polyethylene boards and foils are very chemically resistant, flexible, lightweight, but their connection is imperfect. There are also problems with bonding rubber bands, especially in bends and corners. Moreover, they are difficult to handle due to their large weight. Enamel coatings (polystyrene, epoxy) have a limited service life. Sometimes concrete is protected by fluctuation. Overall, the problem of preventing leakage of water and aqueous solutions in the construction industry is very complicated and today, the state of the art does not yet know the full solution.

We have now found that a new method of impregnation or insulation to prevent water and aqueous solutions from penetrating concrete surfaces results in much better results. First, a dry and clean substrate is primed with an epoxy resin solution with an average molecular weight of 450 to 650. a hardener in an amount corresponding to 90 to

110% of the theory of epoxide groups or epoxyacrylate-based epoxy resin solution with an average molecular weight of 370 to 600 and up to alkyl acrylates, to which an amine hardener corresponding to 90 to 140% of the theory of epoxy and acrylic groups present, or their mixture, then one or two layers of a leveling compound consisting of epoxyacrylate based on an epoxy resin having an average molecular weight of 370 to 600, up to C1 to 6 alkyl alkyl acrylates, fillers and an amine hardener are applied in an amount of 90 to 140% of the theory relative to the epoxy and acrylic groups present. or consisting of a liquid epoxy elastomer of an average molecular weight of 550 to 1000, fillers and an amine hardener in an amount of 90 to 120% of the theory relative to the epoxide groups present, or consisting of a mixture of the above two masses. dripping from epoxyacrylate-based epoxy resin with an average molecular weight of from 370 to 600, to C ^ Q alkyl acrylates and aminic hardeners in amounts of from 90 to 140% of theory relative to the content of epoxy and acrylic groups in the composition, the final protective coating can contain coloring filler or pigment.

The properties of the masses obtained according to the invention can be varied by influencing the density, polarity and topology of the structural network of the mass by changing the quality and quantity of the starting components. By changing the types and proportions of fillers, mechanical and electrical properties (strength, abrasion, surface resistance, etc.) and processability (viscosity, thixotropy) can be influenced. Fillability can also be influenced by the amount of hardener.

Liquid epoxy elastomers are prepared by known procedures from epoxy resins and compounds having an average molecular weight of 170-500 by reaction with polymeric fatty acids or carboxylic low molecular weight polymers having an average molecular weight of 500-4000 and an average carboxyl group content of 1.80-2.07.

Typically, a molar ratio of epoxy compound to polymer fatty acid or low molecular weight carboxylic polymer of 1.9 to 5: 1 is used. They often contain reactive diluents such as aliphatic epoxy resins based on diols. The amine and polyaminoamide curing agents used according to the invention have amine numbers of 150 to 1800 mg KOH / g and cause curing of the liquid compositions of the invention at temperatures of 0 to 60 ° C, at an amount corresponding to 90 to 140% of the theory relative to the reactive group content.

In curing, substances that slow or accelerate the chemical reactions of the compounds in a mixture such as phenolic compounds, water, polyols, thiols, ketones, cyclic ethers and the like can be used. Sometimes it is appropriate to use substances affecting the flow, surface tension and the like.

Common fillers such as graphite, sand, talc, chalk, gypsum, glass flour, diatomaceous earth, ground fireclay, fly ash, cement, corundum and garnet waste, amorphous silica, silica gel, alumina, metal dust, asbestos, powder can be used. polyvinyl chloride and other polymers and copolymers, pigments such as zinc oxide and the like.

The epoxy acrylates formed by impregnation or isolation according to the invention have a ductility of 10 to 50% at a tensile strength of 30 to 70 MPa and an impact strength of 40 to 90 kJ / * v / m. The resulting epoxy rubbers have a tear strength of 10 to 100% and a tensile strength of 3 to 40 MPa. Impregnations are characterized by excellent adhesion, wear resistance, weathering and temperature and water and oil impermeability. These good properties can be used especially in agricultural construction, repair of swimming pools, concrete tanks and so on.

In penetration, it is preferred to use an aromatic hydrocarbon such as toluene as solvent. The use of ketones is less suitable for ketimine formation and slow release from the substrate. Mixtures containing alcohols are less suitable.

The impregnation and insulation according to the invention are carried out by coating, rolling, spreading, gravel, spraying and the like. Multiple layers of the same and different quality can be combined. Perfect mixing of all components and application is essential to ensure that there are as few air bubbles in the protective coatings and layers as possible. Ensure that no moisture or dirt enters the layers between workflows. This could impair the adhesion of one layer to the other. Cement surfaces must be dry, stiff, slightly rough, free of cement milk, dust and loose particles, free of oils and grease or other impurities that could impair adhesion. If desired, the surface may be sandblasted or pressurized, flamed, abraded, and the like. The treads, such as steps and upper edges, should be treated anti-skid so that they are sprinkled with sand after application of the reactive composition.

For example,

Repair of an older fireproof concrete pool with an area of 220 m with concrete expansion joints on the bottom. The surface of the pool was cleaned of asphalt paint, which peeled off in many places. Residues were removed mechanically, yet complete removal was not achieved. The spray gun was then penetrated with the following system:

37.0 wt. parts of an epoxy resin having an average molecular weight of 546,

2.8 wt. parts of diethylenetriamine and 78.0 wt. of toluene at a temperature of 15 to 17 ° C. The following day, the loosened expansion joints were sealed with non-slippery putty

24.3 wt. parts of epoxyacrylate resin consisting of 70 wt. % of an epoxy resin having an average molecular weight of 588 and 30 wt. % 2-ethylhexyl acrylate,

60.8 wt. parts of fine waste from hardened paper and fabric butchers,

2.9 wt. parts of diethylenetriamine and 12.2 wt. parts of blue two-component epoxy paint.

Depressions and cracks in the walls were also filled with this putty. Temperature 17 ° C. The gelling of the putty was carried out in 45 minutes without major exotherm (about 40 ° C in the rest). After two hours the layer was sprayed with the following composition:

47.6 wt. parts of the epoxyacrylate resin mentioned above,

47.6 wt. parts of toluene and

4.8 wt. parts of diethylenetriamine.

The next day it was raining and therefore the surface layer was applied after two days in the following composition:

79.4 wt. parts of epoxyacrylate resin consisting of 80 wt. % of an epoxy resin having an average molecular weight of 502.3 wt. % n-butyl acrylate and 17 wt. % 2-ethylhexyl acrylate,

70.0 wt. parts of toluene

2.4 wt. parts by weight of the above blue two-component epoxy paint, and 18.0 wt. parts of trimethylhexamethylenediamine, at 24 ° C.

Example 2

For comparative testing of the impregnation methods, concrete tiles (pavement size, 20x20x4 cm, of second class concrete) were built into the 2x1x0.6 m wooden crate to form a pit with sloping walls (about 60 °). The joints between the tiles were filled with cement had ^H ou. After two months of maturation, three wells were impregnated as follows:

well A - penetration into the spray gun saturation by a system consisting of 70 parts by weight of epoxide resin with a mean molecular weight of 565, 30 parts of 2-ethylhexyl acrylate, 8.7 parts of diethylenetriamine and 75 parts of toluene at 22 ° C. Next *

On day 2, a basic cementation of 100 parts of liquid epoxy elastomer with an epoxy group content of 0.246 mol / 100 g, 15 parts of finely divided graphite and 10 parts of trimethylhexamethylenediamine was performed. After 8 hours, a second bonding layer of 80 parts of an average molecular weight of 435 epoxy resin, 5 parts of n-butyl acrylate, 15 parts of 2-ethylhexyacrylate and 14.5 parts of tetraethylenepentamine, 200 parts of fine hardened paper and fabric cutter was applied, and 40 parts. parts of a two-component epoxy blue paint at 20 ° C. The next day, a coating consisting of 70 parts of 80 wt.% Epoxy acrylate resin was sprayed on. parts of epoxy resin having an average molecular weight of 500, 3 wt. % n-butyl acrylate and 17 wt. % 2-ethylhexyl acrylate, 80 parts toluene, 3 parts blue epoxy two-component paint and 20 parts trimethylhexamethylenediamine, at 24 ° C.

Well B - penetration the same as well A. The next day, it was cemented with a system of 50 parts of an average molecular weight of epoxy 606, 80 parts of an average molecular weight of epoxide 400, 20 parts of 2-ethylhexyl acrylate,

300 parts of diatomaceous earth and 23 parts of dipropylene triamine at 23 ° C.

The surface layer is made three times as with the well A.

Well C - three times brushed with asphalt paint (Estadien), at 25 ° C.

The wells were placed in a shed under the roof and filled with water. In 6 months, the level dropped by 15 mm for the well A, by 12 mm for the well B, as well as for the metal tray and by 50 mm for the well C already after 6 weeks.

Claims (2)

Method for impregnating or insulating water and aqueous solutions from concrete surfaces, characterized in that the dry and clean substrate is first primed with an epoxy resin solution having an average molecular weight of 450 to 650, to which an amine hardener corresponding to 90% is added before use. up to 110% of the theory of epoxy groups, or epoxyacrylate-based epoxy resin solution with an average molecular weight of 370 to 600 and up to alkaloacrylates, to which an amine hardener corresponding to 90 to 140% of the theory with respect to both epoxy and acrylic groups present is added before use; or a mixture thereof, then applied with one or two layers of skim plaster consisting of epoxy acrylate, epoxy based average molecular weight from 370 to 600 C ₄ to C _1Q alkylacrylate aminic hardeners and fillers in an amount of from 90 to 140% of theory relative to p epoxy and acrylic groups present, or consisting of a liquid epoxy elastomer of an average molecular weight of 550 to 1000, fillers and an amine hardener in an amount of 90 to 120% of the theory relative to the epoxy groups present, or consisting of a mixture of the above two; epoxy acrylate composition consisting of epoxy resin of average molecular weight 370 to 600, C, to C ₄ alkyl acrylates and _Q1 aminic hardeners in amounts of from 90 to 140% of theory relative to the content of epoxy and acrylic groups in the composition. 2. The method of claim 1 wherein the last protective coating comprises a colored filler or pigment.