1. Material introduction
Water-based polyurethane waterproof coating is a high-tech product developed by introducing foreign advanced technology.This product belongs to molecular polymer elastic waterproof material.The product is non-toxic and tasteless, has good bonding and water resistance, and has strong adhesion to mortar, cement-based stone, stone and metal products. The chemical property of the product is stable, can withstand long-term sunlight exposure, high strength, large elongation, good elasticity, good waterproof effect.
2. Material characteristics
1, single component, cold construction, non-toxic, tasteless, safe to use.
2, in the wet (no water) or dry base surface construction, coating tough high elastic.
3, for masonry, mortar, concrete, metal, foam board, insulation layer has a strong adhesion.
4, construction safety, simple, short construction period.
3.The scope of application
The product is suitable for national key project and general waterproof project, such as roof, color steel tile, basement, civil air defense project, kitchen and toilet, culvert, tunnel, bridge, pool, etc. , pool and other projects of anti-corrosion and wood floors, cement panels, asbestos products, glass fiber reinforced plastic products, ceramic products, tiles and other bonding, but also can be used in the building structure of the joint materials.
4.Preparation for construction
1 materials and requirements
(1) waterborne polyurethane waterproof coatings, should have factory certification and factory product certification documents, and re-check the technical performance.
(2) supporting materials:
2 main tools:
(1) motor tools: electric mixer.
(2)Hand tools: mixing pail, small iron pail, Small flat shovel, plastic or rubber scraper, rolling brush, brush, spring scale, fire fighting equipment, etc. .
3.Operating conditions:
(1) For cold-work construction of polyurethane waterproof coating for waterproof layer, before applying the waterproof layer under conditions with high groundwater level, the groundwater level should be lowered first and drainage treatment should be carried out to reduce the groundwater level to 300mm below the operating elevation of the waterproof layer and maintain it until it is waterproof. Layer construction completed.
(2) The base layer on which the waterproof layer is applied should be leveled according to the design. It is required to be smooth, calendered, solid and flat, without sand, with a moisture content of less than 9%. The yin and yang corners should be rounded.
(3) Before applying the waterproof layer, dust, debris, residual mortar lumps, and protruding parts on the painting surface should be dealt with and cleaned.
(4) Painting of water-based polyurethane shall not be carried out under rainy conditions, and the ambient temperature during construction shall not be lower than 5°C.
5.Operating process
1.Process flow: Cleaning the base → Applying primer → Construction of waterproof layer → Making protective layer
2.Base layer treatment: Before applying the waterproof layer, clean the debris, mortar lumps, etc. on the surface of the base layer first, and wipe it once with a clean wet cloth. Only after checking that the base layer has no defects such as unevenness, cracks, sand, etc. can the next step be carried out. process.
3.Construction of coating waterproof layer:
(1)Additional coating layer: For pipe roots that pass through walls, roofs, and floors, floor drains, drainage outlets, yin and yang corners, deformation joints, and weak parts, the above-mentioned parts should be reinforced with coating before large-area construction of the coating layer ( additional layer). Additional coating method: lay glass fiber cloth in the additional layer of the coating film. During the coating operation, use a board brush to scrape the paint to remove air bubbles, and stick the glass fiber cloth tightly to the base layer. The yin and yang corners are generally strip-shaped, and the pipe root is Block shape, three-sided angle, should be cut into block-shaped cloth and laid, and the coating can be applied multiple times.
(2)Apply the first layer of coating: After the material of the previous coating reinforcement layer has solidified and dried, you should first check whether there are any residual pores or bubbles in the additional layer. If not, you can apply the first layer of coating; If there are pores or bubbles, use a rubber scraper to forcefully press the mixture into the pores, apply the film locally, and then apply the first layer of coating. To apply the first layer of polyurethane coating waterproof material, you can use a plastic or rubber scraper to apply it evenly, and strive to have a consistent thickness of about 1.5mm, that is, the dosage is 2.2-3kg/m².
(3)Apply the second coat of paint: After the first coat of paint has solidified, you can evenly apply the second coat of paint on it. The direction of the paint should be perpendicular to the direction of the first coat of paint. Scratch the second coat of paint. The time interval between the first channel and the first channel is generally not less than 24 hours, nor more than 72 hours.
(4) Scratch the third coat of paint: The scraping method is the same as the second coat of paint, but the scraping direction should be perpendicular to it.
(5)Spread stone ballast sparsely: Before the third coating film is cured, stone ballast with a particle size of about 2 mm is sparsely sprinkled on the surface to strengthen the bonding effect between the coating layer and its protective layer.
4.Coating film protective layer:
There should be no water accumulation or water seepage on the surface of the waterproof layer of the coating film. The protective layer must not have hollows, cracks, or peeling off.
After the last coating is cured and dried, cement pump slurry can generally be applied according to the appropriate form required by the architectural design. A protective layer of fine stone concrete can be poured on the flat surface.
6.Quality Standard
1.Guaranteed items:
(1) The performance of coated waterproof materials and laminated glass cloth must comply with the design and relevant standards. And there are product certificates and test reports.
(2) The coating waterproof layer and its local deformation joints, embedded pipe fittings, and yin and yang corners that should be strengthened must comply with the design requirements and construction specifications, and no water shall leak.
2.Basic items:
(1)The base layer of the waterproof coating should be firm, the surface should be clean, dense and smooth, the inner and outer corners should be arc-shaped, and the primer coating should be even and without leakage.
(2)The application method, overlap, and closing of the additional coating layer should be in accordance with the design requirements. The bonding must be firm, the joints must be tightly sealed, and there should be no defects such as damage or hollowing.
(3)The polyurethane coating is a waterproof layer with uniform thickness and strong and tight bonding. Defects such as shedding, cracking, holes, and loose application and crimping are not allowed.
(4)There should be no water accumulation or water seepage on the surface of the waterproof layer of the coating film. The protective layer must not have hollows, cracks, or peeling off.
7.Finished product protection
1.Pipe roots, embedded parts, and deformation joints that pass through the wall must not be damaged or displaced during coating construction.
2.Before the coated film is cured, no people or objects are allowed to accumulate in order to avoid damage to the waterproof layer of the film and cause leakage.
8.Quality issues that should be paid attention to
1.Pores and bubbles: The material mixing method and mixing time do not mix the materials evenly; during construction, a mixer with a power and speed that is not too high should be used. Another reason is that the base layer is not clean. Before coating, the base layer should be carefully cleaned. There should be no floating sand and dust. There should be no pores on the base layer. The pores in each layer of the coating should be treated according to the process requirements to prevent damage to the coating. causing leakage.
2.Drumming: The base layer is peeling, sandy, cracked, and not dry, resulting in poor adhesion of the coating film; the construction of the base layer should be carefully operated and maintained. After the base layer is dry, apply the primer first, and after curing, follow the construction process of the waterproof layer. Apply layer by layer.
3.Warping of the coating film: The edge of the waterproof layer and the overlap of the sub-brushes peel off from the base layer and warp. The main reasons are that the base layer is not clean or dry, the closing operation is not meticulous, the sealing is not good, and the adhesive force of the base paint is not strong, etc., causing warping. Therefore, the base layer must be kept clean and dry, and the operation must be meticulous.
4.Damage: During the layered construction of the waterproof layer of the coating film or after the entire coating film has been constructed, the coating film is damaged or scratched by people operating or placing tools and materials before the coating film is cured. The integrity of the coating film should be protected during construction.
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