It is common for concrete surfaces to develop cracks over time. Cracks can appear on walls, pavements, foundations or other surfaces. Timely repair can prevent the cracks from spreading, resulting in costly repairs. There are many methods for repairing concrete cracks. The choice of the right method depends on the nature, type, and cause of cracks. The knowledge of the underlying cause can help in preventing the damage from recurring.

Explore the different methods that can be used for repairing cracks.

1. Epoxy Injections

If the crack has an opening of 0.05mm or more, the epoxy injection method is recommended. It is not used for active or large number of cracks. It is also not recommended for cracks with uncontrolled water leakage.

  • Epoxy is injected under the crack
  • The cause of the crack needs to be found and fixed before injecting the epoxy

This technique can be handled only be experienced professionals who have advanced skills and discipline.

2. Routing & Sealing

This is a much easier technique and a more commonly practiced one. It is suited for repairing remedial cracks. It is perfect for inactive cracks that don’t require restoration of tensile strength. The steps involved in the process include:

  • The crack is enlarged along the exposed face
  • V-shaped groove of up to 6mm width and 6-25mm depth are created
  • The groove is filled and sealed using the repair material

When pavements are repaired, hot tar may be poured into the cracks as a simple and cost-effective method. The sealant material must create a balance between regular expansion and contraction. It should not become brittle after some time. Examples of commonly used materials include:

  • Urethanes
  • Epoxies
  • Asphaltic materials
  • Silicones
  • Polymer mortars

Cement grouts are not used because they can become brittle and crack in the future.

3. Stitching

Stitching is a simple yet longer-lasting technetium for repairing cracks in concrete. The process involves drilling multiple holes along the cracked surface. These holes are then stitched together using special U-shaped metallic wires. The wire is passed through the holes and fixed in place using some epoxy-based material or grout.

4. Drilling & Plugging

Drilling and plugging is usually used when concrete has vertical cracks running in straight lines. The steps involved include:

  • Vertical holes are drilled in the cracks
  • Grout is passed down to form a key

The key prevents any potential leakages. This is a quick and cost-effective method of fixing concrete cracks.

5. Grouting Technique

When it comes to the grouting method, there are many sub-methods to choose from.

Portland Cement Grouting

This method is recommended for fixing larger cracks. The cracks are filled with Portland cement grout and works effectively in preventing water leakage.  However, this method is not recommended if there is greater emphasis on ensuring structural bonding of the sections.

Dry Packing

This technique is used for smaller-sized cracks that are not active. Low-water content mortar is placed on the crack and tamped or rammed into place. A lot of specific length and width is opened on the surface before the grout is applied. The mortar is carefully prepared to minimize any chances of shrinkage and applied in layers. Each layer needs to be effectively compacted.

There are many more methods for repairing concrete cracks. Examples include overlay treatment, gravity filling, and surface treatment. You must select a method based on the type and nature of the cracks. You should also consider whether it requires structural repair or not. The best decision is to hire the services of professional experts for the repair work. They can inspect the type of damage and evaluate the underlying causes before determining the best repair method.