Application of polyurethane waterproof coating in basement waterproof construction

Abstract:
Combined with the actual engineering situation of Shenchi high-rise apartments, the construction technology of polyurethane coating waterproof construction in basement waterproofing project is discussed
Key words: high-rise building basement waterproof polyurethane waterproof coating construction technology
1, introduction
With the continuous development of society, high-rise buildings in modern cities have formed a unique landscape. Basement industry has become an indispensable part of modern residents' life, basement waterproofing has attracted more and more attention. At present, basement waterproofing mainly uses the combination of structural self - waterproofing and waterproof material waterproofing. The organic combination of the two, just soft, multi - defense, so that both economical and can achieve a good waterproof effect.
2, engineering overview
project is located in Shanxi, located in the wide valley between the hills, the terrain is relatively flat. Building function for the apartment building, the height of the building 53.5 meters, the ground floor, the design waterproof rating of the second level. Groundwater at the site is the fourth series of gap diving, the water table buried depth of 6.3 to 8 meters, with seasonal fluctuations slightly, the range of change between 2 to 4 meters.
3, polyurethane coating waterproof characteristics
polyurethane waterproof coating at room temperature is a thick liquid, after coating curing, can form a seam-free waterproof coating film; Waterproof surface layer is good overall, especially suitable for waterproof construction in the facade, yin and yang angle, through the structure layer pipe, bulge, narrow place and other detailed structure, and easy to operate, low labor intensity; The coating waterproof layer has good water resistance, weather resistance, acidity and alkalinity and excellent extension performance, can adapt to the needs of local deformation of the grass-roots, at the same time can strengthen its own pull strength by applying the tire body enhancement material, for the grass-roots cracks, structural cracks, pipe roots and other areas prone to leakage, easy to enhance, strengthen and repair treatment.
4, construction method
4.1 construction preparation
the main materials required, auxiliary materials and construction tools preparation
4.2 construction process
4.2.1. clean up to find the flat layer
The low concave part is filled with polymer cement mortar. Looking for a flat surface without dust is important for the quality of the coating waterproof layer.
4.2.2 check to find flat water content
1m2 square coil flat dry paved on the looking flat layer, sit still for 3 to 4 hours to open the inspection, find flat layer cover and roll on the watermark is considered dry.
4.2.3 coating grass-roots treatment agent
the role of the grass-roots treatment agent is to cut off to find the moisture on the stratosphere upward penetration, to prevent waterproof coating film drum off; The flat surface will be further reinforced to improve the bonding strength between the coating film and the base, and prevent the defect of the needle eye pores in the coating.
the grass-roots treatment agent should be evenly applied to find the flat layer, the amount of coating is generally 0.3kg m2 or so is appropriate, not to appear dewy phenomenon. The base glue coating needs to be dried for 4 to 24 hours (depending on the climate) in order to carry out the construction of the next process.
4.3. Preparation of polyurethane waterproof coating
According to the design ratio or the manufacturer's prescribed ratio, its armor and B or A, B and other materials mixed in a mixing barrel, and with an electric mixer stirring, stirring after 5 minutes can be used. Because of the polyurethane waterproof coating coated with waterproof layer, the site should be used up within two hours after preparation. Therefore, according to the project dosing and coating progress, is now ready to use to avoid shelving too long in the mixing barrel reaction curing into blocks.
4.4. Detailed structure enhancement treatment
in the corner deformation seam part, the back pouring belt part, construction, seam pit groove, etc. need to be enhanced in advance of the detailed construction site, according to the width required by the size of the cutting tire body enhancement material, local enhancement construction treatment. Groove seams are embedded with sealing material.
When doing the coating film additional enhancement layer, you can use the tin scraper scrape or small paint brush brush, after the coating is basically dry, and then coat on its surface a second time additional coating, and immediately apply the cropped tire body enhancement material. Tire body enhancement material to be paved with a balanced flat, empty drum and crease phenomenon, so that it is closely bonded to the coating, and then static curing into the tire body reinforced material additional waterproof layer.
4.5. Coating waterproof layer
after the additional layer of the detailed construction site is cured into a film, the waterproof layer can be coated. The thickness uniformity of the coating waterproof layer and the thickness of the waterproof layer are all important factors of excellent waterproof quality. Therefore, in addition to ensuring the thickness of the waterproof layer, but also to ensure the uniformity of the waterproof layer. This can be achieved by layering the coating, each coating should not be too thick. Polyurethane waterproof coating in the flat base can be coated 4 times, each time the amount of coating is 0.6 to 0.8 kg m2; In order to prevent the coating from slipping, the amount of coating should be reduced to 0.5 to 0.6 kg m2 per time, while the number of times the coating should be increased to 5 times.
coating coating, generally need to cure more than six hours, to apply the film basically non-stick fingers, and then coating the second coating. This is mainly to let the underlying coating film has a certain thickness, can make its extension performance to be fully played, the tire body material set on the upper part of the coating, can enhance the synthetic polymer coating waterproof layer of puncture resistance and wear resistance. The coating of the third and fourth times is still coated according to the above requirements. The coating direction between each adjacent coating should be perpendicular to each other. When coating the tire body, the coating should be soaked in the fetal body, covering completely, there should be no tire body exposed phenomenon.
4.6. Coating waterproof layer head, detail structure enhancement treatment
in the painting to the wall pipe, construction seams, deformed seams, rear pouring belt, external wall head and other detailed construction sites, should be enhanced, closed treatment.
4.7. Check the construction quality of the waterproof layer
4.8. Pour the fine stone concrete protective layer on the pad coating waterproof layer
Before pouring the protective layer, in order to prevent damage to the coating waterproof layer when pouring concrete, an isolation layer should be set between the waterproof layer and the fine stone concrete. It is better to use 1:2.5 cement mortar as a protective layer.
4.9. Set the outer wall coating waterproof layer protection layer
using soft material or spread 20mm thick 1:2.5 cement mortar as a protective layer. Soft materials can be made of 5 thick polyethylene foam sheets or 50mm thick extruded polystyrene foam sheets of 20 kg per cubic meter. When pasting the foam plate, the seam between the plate and the plate should be tight to prevent backfilling soil damage to the waterproof layer. Therefore, the sheet and the sheet should be connected by a hook, the width of the lifting is 20 to 30mm.
water-based polyurethane waterproof layer will appear after water "dissolving" phenomenon or reduce waterproof performance, therefore, the surface is coated with a 20mm thick 1:2.5 cement mortar protection layer is better.
5. Construction precautions
Polyurethane waterproof paint is strictly prohibited in rainy days, snow days construction, otherwise in the mezzanine layer into the rain, snow water, will seriously reduce the coating between the coating, between the coating and the grass, reduce waterproof performance. Windy weather at level 5 and above shall not be constructed. At the same time, the temperature is too high or too low weather must not be constructed, otherwise, the quality is difficult to ensure. Polyurethane waterproof coating construction practices can be found in the figure below
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