Chemical grouts represent a large family of predominately urethane-based grouts.
Leaks and infiltration can be controlled in structures such as tanks, vaults, tunnels, concrete dams and below grade pits with this process. In this process, material is placed under pressure, using either single or plural component pumps, then injected through a series of ports. Ports are usually installed by drilling at an appropriate angle into the surface intersecting the cracks / joints and then tapping them in, where they are held in place by friction. In some applications, surface mount ports are installed using an epoxy gel to bond the port to the surface until injection is complete. Reactions are controlled by mixing with a catalyst to achieve a desired "set time," expansion and strength. In place, the grout expansion allows voids to be filled and water controlled. This allows for a flexible "gasket" to stay in place that will tolerate movement, maintaining the watertight seal required.
Bentonite is a blend of natural clay used to waterproof the exterior of below grade structures when injected into the annular space between the soil and foundation walls. Bentonite is injected between the structure and soil by a system of injection pipes driven or jetted into the dirt to a predetermined depth. The grout creates a barrier that remains pliable in the presence of moisture, sealing the structure from water. Without the need to excavate, landscapes can be protected and waterproofing can be accomplished with minimal disruption to normal activity.
Properly grouting machines and equipment bases requires a grout that not only supports loads, but also does not allow shrinkage; or in the case of epoxy grouts, "creep". Precision grouts can be either cementitious or epoxy grouts. It is critical to the selection of grouts that the types of loads, as well as the environment, are fully understood.
Cementitious Grouts: Precision non-shrink cementitious grouts are placed in areas of static and low dynamic load. They also provide a high heat resistance.
Epoxy Grouting: Precision non-shrink epoxy grouts are placed in areas of heavy dynamic loading, vibrations, impacts or situations requiring good chemical resistance.
100% bearing capacity after the grout is placed and cured is critical to the proper performance of precision grouts. It is preferred to have a grout that exhibits a slight, yet controlled, expansion once cured to insure 100% bearing.