Application of water-based polymer modified bitumen waterproof coating in basement side wall waterproofing

Project Introduction

Haoning Jinfuqing is located in Shuangcheng District, Harbin.

The project is planned and designed by the Architectural Design Institute of Tsinghua University, with a total land area of ​​220,000 square meters and a building area of ​​600,000 square meters.

The underground fortification level of the project is Class 1, with strict requirements on the durability and environmental protection of waterproof materials.
Since deep trench excavation project group, the higher the height of side wall underground, construction of the side wall when the anti-slip coating high demand, so development project using Hongyuan waterproof sliding viscous aqueous polymer modified asphalt waterproof coating com" href="http://">paint Online coatingol.
com .

The coating has the characteristics of anti-sagging, anti-slip, strong adhesion, and environmental friendliness.
When it is combined with self-adhesive polymer modified bitumen waterproofing membrane to form a composite waterproofing system, the waterproofing effect is significant, and the construction quality is good.

Waterproof design

1.

Waterproof structure design of basement side wall

The side wall of the basement adopts the waterproof design of 1.

5mm-thick Biogo-WS high-viscosity and anti-sliding water-based polymer modified asphalt waterproof coating and 1.
5mm-thick self-adhesive polymer modified asphalt waterproofing membrane, which effectively guarantees the waterproof effect, as shown in Figure 1.

Figure 1 Waterproof structure of underground side wall

When high-viscosity waterproof coatings are used in combination with self-adhesive coils, the waterproof layer has the advantages of uniform coil thickness and stable quality, as well as the integrity of the waterproof coating film, and the advantages of easy handling of nodes and special-shaped parts; in addition, two Both of these materials are asphalt-based materials with good compatibility.
After forming an integral composite waterproof system, they penetrate each other and are difficult to separate.

2.
Features of main waterproof material

When used in the construction of underground side walls, the high-viscosity and anti-sliding water-based polymer modified bitumen waterproof coating has the following advantages:

1) Anti-sagging of the facade: Traditional paints are easy to sag during facade construction, and it is difficult to reach the design thickness.
Multiple constructions cause waste of paint and construction period, and it is easy to cause paint to accumulate in the inner corners, which affects the film quality and damages the waterproofing.
Integrity.

The high-viscosity and anti-skid water-based polymer modified asphalt waterproof coating is a one-component water-based waterproof coating prepared by using high-quality emulsified asphalt, polymer modifiers and special functional additives.
It can be applied at a time to 1mm thick without sagging , Reduce the number of construction times, shorten the construction period, and the film thickness is uniform, and it is closely attached to the self-adhesive coil.

2) Anti-coil slippage: The coating has high bonding strength with asphalt-based coils and concrete base surfaces, and the peel strength after being combined with self-adhesive coils is greater than 3N/mm, which can be effective after forming a coated-coiled composite system Avoid falling off and slipping of coiled materials caused by waterproof construction and earthwork backfilling, thereby ensuring the quality of waterproofing.

3) Low water absorption: The underground project is in a long-term water environment, and the selected waterproof coating should have good water resistance and durability.
Conventional water-based waterproof coatings have a high water absorption rate due to factors such as the retention of emulsifiers and the selection of pigments and fillers.
The water molecules react with the groups in the polymer and cause the physical properties of the coating to decrease, which affects the service life of the waterproof layer; high viscosity The anti-skid polymer modified bitumen waterproof coating has been improved in formula and technology, and the water absorption rate is only about 4%.
After water treatment, the retention rate of peeling strength with self-adhesive coil and the retention rate of bonding strength with concrete are both at 90%.
The above is applicable to underground waterproofing works.

4) Adapt to the deformation of the base layer: The elastic modulus of the coating is low, and the elongation at break exceeds 800%, so it can release the stress generated by the base layer and effectively ensure that the waterproof integrity of the base layer is not damaged when the base layer is deformed.

5) Convenient construction: The coating can be directly rolled or sprayed on the wet base surface, and the low pressure can be well atomized during spraying construction.
Small spraying equipment can meet the construction needs without increasing excessive construction costs; in addition, 1mm coating film The actual drying time at 20°C is less than 4h, which is greatly reduced compared with the conventional coating drying time, shortening the construction period.

6) Good combination with self-adhesive coiled material: The coating is water-based paint, does not contain softened oil, and has no risk of precipitation.
It is also an asphalt-based product with self-adhesive coiled material and can be cold applied.
The two composites form a perfect side wall Waterproof system conforms to the concept of energy saving and environmental protection.

Waterproof construction

1.

Primary treatment

Before waterproof construction, first remove the release agent and mud on the surface of the base layer to ensure that the base layer is solid, flat, clean and free of defects.

The concrete of the protruding plane and the template splicing joint is polished and polished, and then smoothed with polymer cement mortar; the screw hole of the side wall is first sealed and smoothed with polymer cement mortar, and then painted with asphalt-based joint seal after drying Paste: The connection between the base layer and the protruding structure, and the junction between the plane and the elevation shall be made into a straight arc or slope angle with 1:3 cement mortar, the radius of the internal angle R≥50mm, and the external angle R≥10mm.

2.
Detailed node processing

One-cloth two-coating process is used to strengthen the joints of the yin and yang corners, construction joints, post-pouring belts, and wall pipe roots.

First spray or brush a layer of high-viscosity and anti-sliding water-based polymer modified bitumen waterproof coating on the details, and then pave the polyester non-woven fabric, soak and compact the non-woven fabric, and then apply a coating.

3.
Handling of connecting parts

When constructing the connecting part of the side wall of the bottom plate, first remove the protective layer of the brickwork on the top of the guide wall to expose the part and clean the surface, and then apply the waterproof coating to the base surface of the overhanging bottom plate, and wait for the coating to dry Then use the hot-melt method to reversely paste the water-proof roll material on the high-viscosity anti-slip coating, and roll the exhaust gas to ensure that the roll material is tight; then apply waterproofing on the cantilever bottom plate and the water-proof layer of the swing part Coating, and then pave the self-adhesive polymer modified bitumen waterproofing membrane, and lap it with the waterproof layer of the bottom plate, the overlapping width is ≥150mm, and finally construct a protective layer on the membrane.
The specific structure of the connecting part is shown in Figure 2.

Figure 2 Waterproof structure of the connecting part

4.
Waterproof coating construction

The large-surface construction of the high-viscosity and anti-sliding water-based polymer modified asphalt waterproof coating adopts the spraying method.
When spraying, the pressure of the equipment and the speed and frequency of the swing arm are fixed, and the gun head is vertical to the base surface.
The construction is guaranteed by the "cross method".
The coating thickness is uniform.
The paint is sprayed in 3 passes.
During each coating construction, the previous coating must be fully dried.
Use a wet film thickness gauge to measure the thickness of each pass.
The wet film thickness of the first two passes is controlled at about 1mm.
The third pass is based on Adjust the measured thickness to ensure that the final dry film thickness is not less than 1.
5mm.
The construction effect of the side wall coating is shown in Figure 3

Figure 3 Construction effect of underground side wall coating

5.
Self-adhesive coil construction

After the coating is accepted, the self-adhesive coil should be laid immediately to prevent excessive dust from sticking to the coating surface and reduce the bonding strength between the coating and the coil.
When the side wall coil is constructed, tear the isolation film from the bottom to the top while rolling the coil, and then use a rubber scraper to scrape and exhaust air from the center to both sides, so that the coil and the paint are tightly bonded together.
Adjacent coils are self-adhesive lapped, and the lap width is 80mm.
The construction personnel use a hand-held pressure roller to roll and compact from the inside to the outside perpendicular to the long side of the coil.
The closing part is fastened with a closing bead and sealed with a sealant.
.

In order to prevent damage to the waterproof layer during the earthwork backfilling and compaction process, the protective layer of the side wall waterproof layer should be a brick wall protective layer instead of a soft protective layer.

▼

Conclusion

With the sharp increase in the height of the side walls of the basement, the structure has become more alienated and complicated, and higher requirements for waterproof construction are put forward.

Harbin Haoning Jinfulu adopts a composite waterproofing system composed of coiled material and coating in the waterproofing of the side wall of the basement.