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Magazine "All the business people." The problem of reliable and durable protection of structures and buildings made of reinforced concrete and metal (carbon steel, cast iron, aluminum) against corrosion, and concrete, plaster, brick and other surfaces from the weather remains very relevant to the present. In this case, the problem of maintaining or giving aesthetic form to buildings and facilities also remains of current interest.
One of the most widely used methods of solving these problems is to create a surface protective material of decorative paintwork.
It is obvious that for such coatings greatest interest perform paints of environmentally friendly technologies - water dispersion paints.
Their advantages are undeniable: the complete absence of toxic, with a pungent odor and flammable solvents, fire and explosion safety in the production and in use, relatively low temperature of cure coatings, non-waste technology of production, relatively low cost with high quality characteristics of the formed coatings.
Coating materials from series “UHRA" are indeed such materials.
A distinctive feature of these paints is the presence of specific active anti-corrosive nature of acidic components, which provides:
- Firstly, the high adhesion of the coating by chemical interaction with the surface of concrete / reinforced concrete
- Secondly, the transformation of iron oxides, which form the rust on the steel surface, in a layer of iron tightly bonded with non-metal oxide phosphates, and the inhibition of corrosion processes
Paint "UHRA-1505" (VD-AK-1505) is designed for corrosion protection of reinforced concrete, and also for protection from adverse weather of surfaces of iron-concrete / concrete, brick, cinder block, wood-plate materials (particleboard, DSP, fiberboard, plywood) , hardboard, and asbestos material (slate).
The paint is recommended for painting of facades and interiors, for industrial, civil and housing purposes. The use of acrylic dispersions as film-forming creates a high resistance of obtained coatings from UV radiation and other adverse weather conditions.
The color scheme is provided by a wide range of applied mineral and organic pigments and is determined by the requirements of consumers.
Included in MGSN 2.09-03 "Corrosion of concrete and reinforced concrete structures of transport facilities”.
Permitted for use in buildings of all classes of structural and functional fire safety, including evacuation routes. Allowed to use it for color production and storage facilities, where flammable liquids are manufactured, stored or used.
To get rid of the defects during the preparatory work is recommended to use the putty "UHRA-00504.
Primer "UHRA-0501" provides a consolidation of loose crumbling foundations, and significantly (20%) reduces the paint consumption.
For the interior paint, UHRA-2509" (VD-AK-2509) is proposed.
Paint "UHRA-1503" (VD-AK-1503) is designed to protect against corrosion of the metal (carbon steel, cast iron, aluminum) as a primer, and for finishing. For metal structures, operating in highly corrosive environments, use a combination of coating: as a primer - paint "UHRA-1503" (VD-AK-1503) with overlapping of chemically resistant enamels of XC, XB types.
Recommended for protective and decorative painting of the metal for various purposes (engineering products, pipelines, building structures, bridges, sea and river ships, railway and metro carriages, bus bodies, submersible pumps, industrial fans, etc.).
Public health service authorities allowed its use for corrosion protection of internal surfaces of pipes and tanks of drinking water.
Red-brown, brown, black and green colors are produced.
These paints form a scratch-resistant coatings at temperatures ranging from-60 to +100 ° C in a slightly aggressive media (on SNIP - 03/02/1911 -85), without the humidity limits.
According to their characteristics, coatings formed by the colors of WD-cn-1F are not inferior to conventional coatings, such as oil, pentaphthalic, acrylic, glyptal, etc., and often exceed them:
| resistance to impact, cm, min | 50 | GOST 6806 | | flexibility in bending, mm | 1 | GOST 6806 | | resistance to the static action of water, hours, not less | 48 | GOST 9.403 | | resistance to mineral oils, hours, no less | 24 | GOST 9.403 | | washability, g/m2, not more | 0,5 | GOST 28196 | | lightfastness, h, min | 4 | GOST 21903 | | abrasion resistance, kg of sand, not less | 20 | GOST 8747 | adnation :
- adhesion to concrete, MPa - adhesion to the metal, scores |
3,5 | GOST 28574 | | 1 | the life expectancy based on accelerated testing in a climate chamber, years
| more 10 years | GOST 15140 | Complex tests executed in NIIZhB showed high performance of coatings formed by paints "UHRA-1505" on the surface of structural concrete.
The protective properties of coatings on concrete were assessed by diffusion permeability, water resistance, cold resistance, water absorption.
Damage to concrete structures in aggressive environments are connected, as a rule, with corrosion of armature in consequence of insufficient thickness and density of the protective layer of concrete (cement concrete). Neutralization of concrete with acid phases, in particular, neutralization by atmospheric carbon dioxide (carbonation) is the most typical impacts, which touch nearly all concrete structures. The intensity of the carbonation of concrete is determined by the diffusion permeability of the neutralized surface layer of concrete.
Cracks that occur during the operation of structures accelerate the process of destruction of cement and, consequently, they accelerate the processes of corrosion of reinforced concrete.
Comprehensive tests performed by the laboratory of corrosion and durability of concrete and reinforced concrete structures NIIZhB showed that the use of paint UHRA-1505 for the protective layer increases the frost resistance and salt resistance of concrete and reinforced concrete, significantly reduces the absorption of water, several time increases the duration of the protective layer of concrete for reinforcement, which makes the paint especially effective when it is used as weather-coating.
For the protection of concrete structures that allow the disclosure of cracks during operation (beams, roofs, ledgers, etc.), the formulation of paint "UHRA-1505" on acrylic copolymers as film-forming is developed, the distinguishing feature of which is a high resistance to UV radiation and high elasticity (crack resistance ) of surfaces.
Indicators of fracture and adhesion are crucial criteria for estimating of coatings used for corrosion protection of reinforced concrete structures, in which during operation period the formation and opening of cracks up to 0,3 mm (SNIP-3.2.2001-84 *) is possible under the influence of thermal and mechanical effects .
The obtained data agree well with the existing practice of applying paint UHRA-1505 and the results of observations in a number of years of the state of coating on concrete, plaster and brick.
Paint "UHRA-1505" (VD-AK-1505) is successfully used for painting facades of buildings and structures for various purposes in many Russian cities (concrete and reinforced concrete, plaster, brick and other surfaces). That paint is well proven also for protective and decorative painting of slate.
To obtain the optimum thickness of coatings on 140-160 mm of concrete, paint consumption is 350-380 g/m2.
Along with the protection of reinforced concrete up to date remains an urgent problem of corrosion protection of structures and buildings made of carbon steel and cast iron.
It is known that the rust on the steel surface has a loose structure, weakly bonded with non- acidize metal, and freely flows to its surface the water vapor, oxygen and corrosive gases containing in the industrial atmosphere. In addition, iron oxides are the catalytic converters to the further process of corrosion.
Paint "UHRA-1503" forms on the metal surface dense coating significantly reducing the possibility of penetration to the surface of corrosive gases. In addition, active anti-corrosive pigments convert iron oxides in a layer of iron phosphate tightly bonded to the unoxidized metal.
As it was shown by tests conducted by CNIIS, according to its protective characteristics (water-resistant coating, corrosion resistance under high humidity, temperature, and the additional impact of 3% water solution of sodium chloride) they are 1,5-2 times more efficient than the known primer "Unicor-2 "(VD-cn-0251) and paint WD-KCH-124 (WD-KCH-0586).
Paint "UHRA-1503" has been used successfully for protective coloration of railway cars, buses, industrial fans, submersible pumps, and welded structures for various purposes, including construction, water mains and valves, etc.
The optimum thickness of the coating on the metal surface, formed by two coats of paint "UHRA-1503" is no less than 90 microns at a flow rate of paint 150-180 g/m2.
For practical application is very important to use good compatibility of paint "UHRA-1503" with other coatings, both as a ground, and as a capping layer for finishing. Traces of corrosion on the steel surface do not reduce the quality of coatings produced with these paints. |
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