Polyurethane chemical resins used for grouting started with only two water activated materials which were and still are used for a wide variety of applications ranging from sealing active water leaks to stabilizing soils. The technologies were invented by the Japanese in the late 50’s and purchased by 3M Company who came out with 3M 5600 and 5610 which were the first systems available to the commercial market. These early systems were the basis for what has now evolved into a wide variety of resins, which are available from numerous manufacturers. These first two resins represented both of the systems that are currently ava ilable (they are called hydrophobic and hydrophilic) resins while the number of resins with differing properties has grown tremendously. It wasn’t until the late 80’s, before 2-component, non-water reacted systems became available.Those products are chemically reacted urethanes and do not use water at all. They do not adhere to concrete or stretch in a moving crack, and they are not useful as soil stabilizers.They can be used as joint fillers which are basically dry at the time of application. All of these systems have been proven through long-term durability testing to have a half-life of 175 years when not exposed to UV rays.