Need crack treatment method. Generally can be divided into surface treatment method, pressure grouting method and filling method.
1, surface treatment method
This method is mainly suitable for crack width.
The repair points are as follows:
1) Chisel the surface to expose the structural surface, and clean the surface dirt with a wire brush;
2) fully clean with clear water and dry;
3) Fill the crack surface with elastic coating water-releasing material or polymer mortar, and pay attention to spreading evenly;
4) After the first coating is semi-dry, apply it for the second time, and dry and cure it.
2, pressure grouting method
Pressure grouting is a method to repair cracks by injecting epoxy resin or other bonding materials with low adhesion under certain pressure. This method is suitable for cracks with a width of 0.2 ~ 0.5 mm, and its construction technology can be roughly divided into: crack base treatment → determination of grouting port → embedding grouting nozzle → plugging cracks and leakage testing → pressure grouting → plugging → surface cleaning.
3. Filling method
Filling method is a crack repair method by cutting concrete along cracks and filling repair materials there. Applicable to the case of crack width >: 0.5 mm. In the construction of this method, if it is found that the steel bar has rusted after excavation, the steel bar should be derusted and rusted before filling. For the inclined cracks of reinforced concrete floor slab that often appear in residential engineering, when the cracks run through the thickness of the slab, the repair method of gouging and embedding can be adopted. The method is as follows: First, dig a V-shaped groove with a depth of 40-60 mm and an upper opening width of 40-60 mm along the crack, make a base in the groove with plain cement slurry, then fill the joint with epoxy mortar, fill the rest with epoxy mortar, and level and compact the surface with 1: 1 slightly expansive cement mortar (mixed with 5% drainage powder).