Irreversible Changes in the Grouting Industry Caused by Polyurethane Grouting: An overview of 30 years of polyurethane grouting

Water reactive polyurethane grouts were introduced into the grouting industry during the late sixties by the Takenaka Company in Japan under the trade name TACSS. It became possible to inject “one component” grouts without pot life that do not easily wash out and react with the ground water. Because of environmental scrutiny, the first series of TACCS were replaced by solvent-free, hydrophobic, MDI based polyurethane prepolymers. Whilst remarkable successes were booked in mining and geotechnical engineering projects, more and more these products were used for permanent seepage control for sealing concrete structures. Hydrophilic polyurethanes were also introduced in Japan predominantly for the latter application. They contained solvents and were TDI based. Their high reactivity and high dilution ratio with water made them attractive to practitioners.