Crack injection is the process of pumping slurry or resin into a vacuum to fill the cavities of a concrete slab. Injection work is typically carried out to aid waterproofing or to prevent corrosion of concrete structures. The width of the crack will determine the required viscosity of the injection slurry. Concrete crack injections are used to repair fine cracks and structural damage.
A high-strength material is inserted into the broken surface to effectively seal cracks, prevent leakage and reinforce structural integrity. The required equipment was specially designed by a highly qualified technician to infiltrate any type of cracks with an efficiency rate of 100%. It should be noted that the Province of Ontario Standard Specification OPSS 932 requires the use of high pressure for polyurethane crack injection at government construction sites. Epoxy resins for crack injection are available in a range of viscosities, from ultrafine to pasty, to accommodate cracks of different widths.
Many owners are wondering which method of injection is the best - the injection of epoxy cracks or the injection of polyurethane cracks. The technician's job is to regulate the flow, as well as the pressure of the liquid in the concrete crack for a lasting end result. However, please note that the type of epoxy or polyurethane used and the time required for injection will vary with each job depending on the width of the crack, the thickness of the wall and other conditions. Similarly, crack injection can work hand in hand with carbon fiber reinforcement to stabilize and reinforce the basement walls of poured foundations that have arched and cracked.
Polyurethane crack injection kits are recommended for non-structural leaky cracks resulting from concrete shrinkage or minor settling, while epoxy injection kits are designed to treat more serious cracks that compromise the structural integrity of the wall. The expansive and forceful nature of polyurethane, as well as its increased reactivity in the presence of moisture and its flexibility once cured, make it the resin of choice for most repairs of leaking foundation cracks. Polyurethane foaming resins are designed to expand with water to temporarily block the passage of water through the crack or vacuum. The secret to effective injection of cracks, whether epoxies or polyurethane foams are used, is the gradual introduction of the liquid polymer into the crack at low pressures (20 to 40 psi).
At higher pressures, the liquid has enough force to overcome gravity and climb up the crack without filling the back, which is normally narrower than the front of the crack. But in some cases, you may need to follow other corrective measures, along with crack sealing, to ensure a complete solution. In voids, cracks and joints with high water intake, pre-injection is required as a temporary stop of water with a polyurethane foam resin. You can choose between crack repair kits that use injectable polyurethane foam or epoxy, depending on the type of cracks you have.