How to repair basement floor and side wall leakage?

Due to the influence of factors such as heat of hydration generated by cement and water in the concrete, dry shrinkage of concrete, temperature changes, and inconsistent settlement of the basement floor, the poured concrete is not compacted or is poured in two stages, and cracks will appear (overcome Cracks appear in concrete, which is currently a problem in the world), and will pull the waterproof layer away. When the crack width reaches or exceeds 0.2mm and is a penetrating crack, once it contacts the external water source and generates a certain water pressure, water will flow from the concrete crack. gushing out, resulting in water leakage.

Maintenance proposal

Floor curtain grouting (partial overall maintenance, extending several meters around the leaking part)

1. Expand plum blossom-shaped exploration holes in the leakage area and outwards around the outside. The drilling spacing is determined according to the site conditions, and the drilling depth is to the soil layer outside the structure;
2. Pour the hydrophilic elastic plugging grouting materials one by one through the grouting needle;
3. The grouting material is diffused, covered and superimposed on the outside of the structure by pressure pouring. The grouting material also reacts and aggregates water together during the reaction process, consolidates the soil layer, and forms an integral plastic waterproof belt on the outside of the structure;
4. Plug the grouting hole.

Grouting treatment of floor cracks (partial overall repair, extending several meters around the leaking part)

1. Remove the leakage part of the bottom plate and expand the surface of the bottom plate for a few meters to the surrounding area with a fine stone concrete protective layer with a thickness of nearly 100 mm, clean the surface of the bottom plate, and find the cracked part;
2. Work exploration holes (drilling oblique holes) on both sides of the crack, the spacing of the drilling holes is determined according to the site conditions, and the drilling depth is half of the thickness of the foundation raft;
3. Pour elastic anti-seepage grouting material until another hole emerges, so that the grout fills the crack. Then pour the next hole, and all the defective parts in the concrete structure will be filled and compacted to block the water source;
4. Plug grouting holes;
5. The cracks on the surface of the raft are chiseled with “V”-shaped grooves and plugged with plugging materials;
6. Use a chisel to chisel the surface of the raft structure to a depth of several millimeters to fresh, solid concrete. Wet the chiseled surface with clean tap water, but there should be no clear water. Brush the uniformly mixed impermeable slurry on the surface of the treated concrete base for several times. The brushing time interval is a certain time, and it should be brushed back and forth in the cross direction, and it can be properly sprinkled for maintenance;
7. Install tens of millimeters of drainage board on the surface of the treated raft and connect it to the nearby drainage ditch;
8. Restore the C20 fine stone concrete protective layer on the surface of the raft and make it flush with the original ground. The concrete is equipped with steel bars with a diameter of 6mm.

In view of the water seepage in the basement, there are four main reasons:

First, the design reason

1. One-sided emphasis on the self-waterproof function of the structure, and no flexible additional waterproof layer. Structural concrete is a heterogeneous composite material composed of several materials, with many pores of different sizes inside, usually channels for water seepage. Even if the compactness of the concrete itself is improved by various means, the seepage rigid structure of the basement still cannot resist the action of external forces such as earthquake, temperature difference deformation, uneven settlement, etc., resulting in cracks in the structure and the formation of leaking water channels.
2. In the basement of some projects, the bottom plate is not designed with a waterproof layer, or the bottom plate is used for internal waterproofing and only a waterproof layer is set on the outer facade of the enclosure wall, so that the waterproof layer does not cross the circle, and the overall airtight state cannot be achieved, resulting in leakage of the basement. , which is not uncommon.

Second, the material reason

1. The selection of waterproof concrete raw materials is not good, the cement grade is too low, the expired agglomeration, the aggregate particle size does not meet the requirements, the mud content is too large, the quality of the admixture is not qualified, etc., resulting in leakage of the basement.
2. Improper selection of flexible additional waterproof layer. For example, ordinary paper tire linoleum or jute tire linoleum with poor durability is used; the thickness of the waterproof membrane used is too small, which is not resistant to puncture and is easily damaged; the water-emulsion type coating is used for the waterproof layer of the coating film. Re-emulsification occurs and deteriorates, and the waterproof ability is lost, resulting in leakage of the basement; when using synthetic polymer membranes, no supporting adhesives are used.
3. The higher the grade and impermeability level of concrete used as a self-waterproof structure, the more cement is used per unit volume. As a result, a large amount of hydration heat is accumulated inside the concrete. During the cooling process, the concrete shrinks due to temperature difference, causing cracks in the structure. In addition, the current basement structure mostly uses pumped high-strength anti-seepage concrete, and the unit cement consumption and water-cement are relatively large, resulting in shrinkage cracks in the structure.
4. For other reasons, the construction unit used inferior waterproof materials or cut corners. For example, the thickness of the waterproof layer of the coating film was too thin to meet the requirements, and the waterproof effect could not be achieved, resulting in leakage of the basement.

Third, construction reasons

1. Poor foundation disposal, uneven settlement of buildings, resulting in structural cracking and waterproof layer damage to basement leakage.
2. The construction quality of waterproof concrete is poor. Including the lack of strict control of concrete mix ratio and water-cement ratio, poor vibrating, poor maintenance, honeycomb, pockmarked surface, holes and other problems, resulting in the lack of dense concrete in the basement structure and many leaking water channels.
3. The construction quality of the flexible waterproof layer is poor. Including the construction of the base layer not meeting the requirements, the corners are not strengthened; the pipelines through the wall, the embedded parts, the deformation joints and other parts are improperly disposed of, and the bonding between the coil and the coil is not strong.
4. The coating film waterproof layer adopts the construction method of external prevention and internal brushing. Due to the low strength of the coating film and the firm bond with the maintenance wall, when the main structure settles, it is easy to crack the coating film waterproof layer and cause the basement to leak. .
5. The backfill soil contains garbage, broken bricks and other debris, or it is not compacted, so that a waterproof curtain cannot be formed, and a catchment area is formed around the basement. When there is a problem with the structure and waterproof layer, basement leakage will occur.

Fourth, management reasons and other factors

1. Poor management, unreasonable arrangement of construction procedures, random openings in side walls or bottom plates with waterproof requirements, buried pipes, but not careful waterproof repairs, resulting in leakage of the basement.
2. The leakage of the basement caused by the structural damage caused by non-human factors such as earthquakes.