Concrete is a vital construction material extensively used in buildings, roads, bridges, and dams. However, like most commonly used construction materials, concrete may develop cracks over time. This is because crack not repaired can continuously expand until it becomes dangerous enough to cause structural failure. Repairing a cracked concrete is both time and cost-constrained, and as such, adopting the right concrete crack repair method is important so as to significantly save time, money, energy while producing a long-lasting result.
Understanding the type and nature of cracks that have occurred in a building is the first step towards selecting the most effective method of concrete crack repair. Common crack types include horizontal, vertical, diagonal, and step cracks.
A simple concrete crack repair for a small vertical or diagonal crack without signs of distress may involve filling voids with additional concrete to keep moisture out. Otherwise, the following top crack repair methods are usually adopted.
Epoxy injection for concrete crack repair is useful for filling cracks as narrow as 0.002 inches (0.05 mm). The technique here generally involves establishing entry and venting ports at close intervals along the cracks, sealing the crack on exposed surfaces, and subsequently injecting the epoxy under pressure. However, unless the underlying cause of the cracking has been corrected, it will probably recur near the original crack.
The efficiency of epoxy injection is greatly affected by problems such as silt contamination and leakage, both of which need to be fixed for epoxy injection to last. This crack repair method requires someone with the right combination of skills, discipline, and tact for successful execution.
This method is unsuitable if cracks are active and in large numbers, as well as if water leakage cannot be controlled. On exposure to fire and elevated temperature, epoxy resins lose strength significantly and thus may require fireproofing.
Routing and Sealing
Routing and sealing is the simplest and most common concrete crack repair method. The idea here is to treat the crack like a joint. The technique simply involves enlarging the cracks on the surface and then sealing them with a joint sealant. However, it is vital to adopt the right width to depth aspect ratio when sealing the joint so as to leave enough room for movement. This method is unsuitable for structural repair, serving only as a remedy for minor cracks.
Stitching the Crack
Just like the name implies, the crack can be stitched as a form of repair. The procedure involves drilling an entry and exit hole across the cracked surface and running a number of U-shaped metallic staples through the holes, anchoring them firmly in the hole using either an epoxy-based system or grout. This repair method is efficient and long-lasting.
Drilling and Plugging
This method is recommended for its cost and time efficiency. However, it is only suitable for repairing vertical cracks running in straight lines. During this procedure, a series of vertical holes are drilled in the crack and grout is passed down the holes, forming a key. The key prevents leakages and loss of soil from the wall.
Other concrete crack repair method includes gravity filling, dry packing, overlay and surface treatment, etc. Which is best for a specific case is largely the decision of the concrete service expert. If you have questions about concrete crack repair, contact us today.