When a crack affects the performance of the structure, then we will repair it to restore its structural properties. Epoxy injection is typically the basis for this type of repair, with or without added reinforcement. The injected epoxy (like those made by Rhino Carbon Fiber) is actually stronger than the concrete and can restore the concrete strength, but if there is an underlying problem, such as an overloaded structure or some movement condition, the concrete will simply crack again in another location.