Epoxy injection is a concrete repair method that involves injecting epoxy/PU resin into cracks or voids in concrete structures. This method is recommended in several conditions, including:

Structural damage: Epoxy injection is recommended for repairing cracks or structural damage in concrete structures. The method involves injecting a low viscosity resin into the cracks, which then hardens and bonds the concrete together, restoring its structural integrity.

Water infiltration: Epoxy/PU injection can also be used to seal cracks that allow water to infiltrate the concrete. Water infiltration can cause further damage to the concrete and weaken its structural integrity over time.

Chemical resistance: Epoxy injection can also be used to improve the chemical resistance of the concrete. This is particularly important in structures that are exposed to harsh chemicals, such as wastewater treatment plants or chemical processing facilities.

Aesthetics: Epoxy injection can be used to improve the appearance of the concrete. By filling in cracks and voids, the surface of the concrete can be smoothed out, giving it a more polished and finished appearance.

In general, epoxy injection is recommended for repairing cracks or voids that are less than 0.05 inches wide. However, the effectiveness of epoxy injection depends on the extent and nature of the damage. Concrete injection is a cost-effective and efficient method of repairing and strengthening concrete structures. The type of injection material used, such as epoxy or polyurethane, depends on the nature and severity of the damage to the concrete structure. A professional assessment of the damage and consultation is needed to determine the most effective repair method and ensure the long-term durability of the concrete structure.