In PU injection grouting, specialized equipment pumps polyurethane grout under high pressure through drilled packers into leaking cracks or honeycombed areas. The hydrophobic or hydrophilic resin expands up to several times its volume upon contact with moisture, filling voids completely and creating a watertight barrier. Commonly used for negative-side waterproofing in underground str... https://shakuraconstruction.sg/pu-injection-grouting-singapore/