... No shrinkage 3. 9kg JBY-668 Hydrophobic Polyurethane Foaming Agent For Waterproof Product DescriptionSingle-liquid type with simple construction, hydrophobic, non ... Besides, it don’t damage or corrode steel reinforcement in RC structure and is easy to remove the spillage on the ... wall in the basement / secondary joints, cracks of RC structural, small holes, tunnel, subway, box culvert, wall, etc. ...