Waterproofing

Waterproof engineering is a systematic engineering, it involves waterproof materials, waterproof engineering design, construction technology, building management and other aspects. Its purpose is to ensure that the building is not eroded by water, the internal space is not harmed, improve the use function of the building and the quality of production and life, and improve the living environment. Including roof waterproof, basement waterproof, toilet waterproof, external wall waterproof, subway waterproof and so on.

Importance

Offices, computer rooms, workshops and other workplaces such as long-term leakage will seriously damage office facilities, precision instruments, machine tools and equipment can also fail due to mildew, and even cause electrical short circuit. In the face of leakage, people have to spend a lot of manpower and material resources to repair every few years. Leakage not only disturbs people's normal life, work and production order, but also directly affects the service life of the whole building. It can be seen that the quality of the waterproof effect is crucial to the quality of the building, so the waterproof project occupies a very important position in the construction project. In the construction of the whole building project, we must strictly and seriously do a good job of building waterproofing.

Main construction technology

Structural concrete self-waterproofing measures
In the waterproofing project, the rigid self-waterproofing of the waterproof concrete of the main body and the auxiliary structure can not only improve the crack and seepage resistance of the concrete, but also improve the waterproof and crack resistance of the whole concrete to a certain extent.
Main construction measures
The high performance admixture is used to shrink waterproof concrete, and the coarse and fine aggregates in the construction are controlled, which can improve the overall quality of concrete and ensure that the impermeability grade of concrete meets the relevant requirements and standards. It is necessary to ensure the thickness of the entire waterproof structure in strict accordance with the relevant design proportion, and after several designs and repeated tests, the pouring method is finally determined. The use of "double mixing" technology, that is, mixing high-efficiency water reducing agent and fly ash, can reduce the amount of cement, reduce the heat of hydration, and reduce the appearance of shrinkage cracks as much as possible. The measurement, mixing and transportation of concrete need to be monitored throughout. In the area where the structure is subjected to shear force, the structure construction joint needs to adopt corresponding measures to avoid the contact between the internal device of the concrete and the formwork, the thickness of the protective layer of the steel bar on the water surface should not be greater than 50 mm, the width of the structural crack should be less than 0.2 mm, and the phenomenon of through cracks cannot occur during this period.

Waterproof concrete
As we all know, self-waterproofing of concrete structure is the most basic content of structural waterproofing in the construction of subway waterproofing project. Among them, in the construction process, the water-cement ratio, the amount of cement and the sand rate should be strictly controlled to fundamentally ensure the quality of concrete. Water reducing agent or expansion agent should also be added in time to enhance the crack resistance of concrete when the shrinkage rate of concrete is reduced. In general, when adding cement, the cement needs to add 300 kg/m3. In order to improve the workability of concrete, it is necessary to appropriately reduce the water-cement ratio, add water reducing agent, and control the dosage at about 0.9%. When selecting the aggregate, its diameter should be less than 4cm, and the grading is good, and the void volume between the aggregate should be reduced. Select medium sand, the mud content shall not exceed 3%, the sand rate shall be about 40%, the lime sand ratio shall be between 1:2 and 1:3, and the collapse rate of pumped concrete shall be less than 15cm. When controlling the construction process of concrete, it is necessary to fill the mixture in the whole model to ensure the integrity and average of the mixture. No segregation occurs. The steel bars inside the concrete, do not touch the formwork, to ensure that the mold frame is stable. Before construction, it is necessary to use cement mortar of the same grade and strength to moistens the pipe, and when the pump is fed into the mold, it should be symmetrical to achieve continuous pouring.

Treatment of construction joints
When concrete is poured, cement mortar is laid on the base surface of the construction joint, and its content should be consistent with the grade of concrete. It is also necessary to vibrate the concrete when it is poured, so that the new concrete is perfectly integrated with the old concrete.