Properties of PU (Polyurethane)
Polyurethane is a fluid resin which is injected into concrete cracks, rock fissures, expansion joints and other voids in concrete structures. When used in concrete crack injection applications the polyurethane is injected into a crack; within minutes the polyurethane undergoes a chemical transformation from a liquid to a solid.
The versatility, and consequently the popularity, of polyurethane resins in crack injection applications stems from polyurethane’s properties:
It has a very short cure time, making it ideal for active leak sealing.
Extremely low viscosity allowing for even the finest fishers (cracks with a width less than 0.2mm) to be sealed.
The resin cures normally whether a foundation crack is wet, actively leaking, or damp.
There are literally thousands of polyurethane resin formulations which is useful when repairing foundation cracks because the viscosity of the resin and cure time can be controlled.
Polyurethane, once cured, can be quite flexible, allowing for movement in the structure and leak leaks to remain sealed.
Any leak in a concrete structure can be sealed.