Principles of crack treatment:
1) First of all, it should be able to ensure the original bearing capacity, integrity, waterproof and impermeability of the structure after crack treatment;
2) Secondly, the influence of temperature and shrinkage stress for a long time should be considered to avoid new cracks after treatment;
3) Again, further man-made damage to structures and components should be prevented, major repairs should be avoided as far as possible, and the appearance of the original structure should be kept as much as possible.
The types of cracks are different, and the methods of repair and treatment are also different. The general treatment methods for cracks are as follows:
01 Surface Repair
Improves water resistance and durability by sealing cracked surfaces. It is suitable for fine and shallow cracks that are difficult to pour into with grout that has no effect on the structural bearing capacity, and micro cracks whose depth does not reach the surface of the steel bar (generally less than 0.2mm in width).
The materials used for repair must have airtightness, impermeability and aging resistance, and must be compatible with the deformation of the concrete. When dealing with large areas, care should be taken to prevent hollowing and peeling.
Surface repair methods mainly include surface coating of epoxy resin, polyurethane, polymer mortar, etc., and surface bonding often uses glass cloth, carbon fiber cloth, and geomembrane.
Before repairing, the dust and scum near the cracks should be removed, and the structural surface should be polished when the surface is pasted and closed.
