Epoxy Injections are a specialized repair method involving injecting a two-part epoxy resin into cracks, voids, and other damaged areas in concrete structures.
In this article we will cover:
What is an Epoxy Injection?
Epoxy is a specific type of synthetic polymer resin that is water insoluble with high adhesive properties with many customizable uses in both commercial and residential settings. Epoxy injection is a specific application process in which specialized equipment pressurizes the epoxy before it is injected into cracks or voids in concrete or other materials. The pressurization allows the epoxy to penetrate the crack completely and fill all angles and crevices, whether visible or invisible. When applied and cured properly, the resulting bond between epoxy and the host material is often stronger than the original material itself. The pressure of the injection method ensures expansive, three-dimensional coverage, as opposed to applying epoxy to the surface via painting or brushing.
Epoxy Injection for Crack Repairs
When cracks, voids, and damaged areas occur in concrete, the structural strength and integrity of the material can be reduced by 40% or more. Repairing cracks in concrete is necessary for both aesthetics and safety and understanding the nature and size of the cavity ensures that the correct type of epoxy can be applied. For example, cracks that are still active or moving require a more flexible epoxy solution than cracks that have settled and become dormant. Hiring a professional contracting company that specializes in concrete assessment and damage repair is essential because they can utilize the correct type and application method for the circumstances.
Injecting epoxy is one of the most effective repair methods for cracks in concrete. The adhesive and expansive nature of the pressurized epoxy creates a new bond between itself and the surfaces to which it is applied. This restores the strength of the concrete while sealing and protecting the material against moisture and corrosive contaminants that might damage the internal structures of reinforcing bars (rebar). The low-viscosity option of epoxy also creates a wide spectrum for applicability. From one end of the damage scale to the other, epoxy can be injected into hairline cracks to prevent future deterioration or it can be utilized to repair structural damage caused by pressure on load-bearing components.
Hydraulic Cement or Epoxy Injection?
Hydraulic cement is a specific type of cement, typically a mix of calcium, silica, alumina, and iron oxide. It differs from regular cement in that a dry, powdered mixture produces a chemical reaction when mixed with water which creates new chemical bonds between the materials. Hydraulic cement is cheap, easy to use, and it sets and hardens within 10 to 15 minutes, making it an ideal tool for fast repairs or emergency use. Because water is the catalyst for the hardening process, hydraulic cement has the unique ability to repair active leaks or even fill cracks that are completely submerged underwater. Once hydraulic cement cures, it is completely impenetrable to water, so professionals will often use it to seal leaks; however, care must be taken to maintain the proper temperature and moisture level to complete the chemical reaction over approximately 30 days.
Although hydraulic cement and epoxy injection have some overlapping functions in their ability to repair cracks in concrete, there are some key differences. Epoxy injections typically require a dry surface, so hydraulic cement is the better choice for repairs where liquid is present. If the repair will impact the structural integrity of a project, epoxy injections provide the necessary strength, because the bond between the epoxy and concrete is much higher than the bond between hydraulic cement and concrete. Hydraulic cement has a faster setting time, which can be useful in projects where speed is critical; but greater attention to detail is needed to apply the cement correctly before it sets. The slower speed of the pressurized, injected epoxy means the epoxy expands into all available space, creating a molecular bond that covers every nook and cranny of a void.
