What should I do if there are cracks in the concrete floor (1)?

1) Self-closing method.

Concrete relies on itself to close the cracks called "self-closing", which is a phenomenon that occurs when moisture is present and there is no tensile stress (Husqvarna 2 Segment Diamond Grinding Bar).

Mechanism: Due to the presence of carbon dioxide in the surrounding air and water, the calcium hydroxide in the cement slurry is carbonized, resulting in the precipitation and growth of calcium carbonate and calcium hydroxide crystals in the cracks.

The combination and interweaving of crystals produces a mechanical bonding effect, which is strengthened by the chemical bonding between adjacent crystals and between the crystals and the surface of cement slurry and aggregate. Finally, the tensile strength of the concrete cracks is restored to a certain extent, and the cracks are also Was sealed.

Mainly used to repair structures in humid environments.

2) Surface sealing method.

This is the simplest and most common method of crack repair.

It is used to repair static cracks that have little effect on the structure, and prevent the intrusion of water vapor, chemicals and carbon dioxide by sealing the cracks.

3) Resin infusion method.

Epoxy resin is the most common crack pouring material. It has high mechanical strength and can resist most of the chemical erosion encountered by concrete. The resin can be poured into the cracks of 0.05 mm.

Except for some special epoxy resins, when the cracks are active, leaky, unable to dry out, or the number of cracks is extremely large, it is usually not easy to use the resin infusion method.

4) The nailing is legal.

When the tensile strength of the main fracture section must be restored, the nailing method is more appropriate.
It is especially suitable for locking active cracks in situations where the surrounding structure will not be damaged.
Use relatively thin and long metal "stitched u-nails" to cross the cracks and insert them into the grooves that have been made in advance, and fix them with non-shrink mortar or epoxy-based adhesives.

5) Drilling impaction method.

This method is usually used to inject cracks in walls.

’If sealing and waterproofing are required, the holes should be filled with flexible asphalt instead of mortar; if the plug is more important, the holes should be filled with epoxy resin.

6) Pasting method.

This method can be used when the movement does not only act on a plane, or when the excessive movement has exceeded the allowable range of a normal-sized groove, or when the groove cannot be cut.

Cover the cracks with a flexible sealing tape, and only stick the edges of the tape.

7) Grouting method.

   * Ordinary cement grouting large-volume dams, thick concrete walls, or cracks in the rock foundation of hydraulic structures are sometimes sealed by injecting Portland cement mortar.

   *Polymer infusion is based on the grouting material of urethane or acrylamide polymer, which reacts with water to form a solid precipitate or foam material to seal the cracks. Can be used in humid environments.

8) Flexible sealing method.

It is usually more appropriate to transform active cracks into motion joints.

Make a groove along the edge of the crack and fill it with a suitable flexible material.

Use an isolation layer at the bottom of the joint.

9) Additional reinforcement method.

   * Ordinary steel bars first seal the cracks, then drill holes about 90° through the crack plane, inject epoxy resin into the holes, and then insert the steel bars into the holes to bond them into a whole.

   * Externally applied pre-stress is applied by post-tensioning method to strengthen the main part of the structure or close the cracks.