Developed many years ago, chemical grouting is the oldest and best method for impeding ground water infiltration into structurally sound sewer systems. Chemical grout is injected through leaking joints, cracks, faults and voids at lateral openings and other areas. The most common points of entrance for ground water infiltration are in manholes at joints and service line connections.
Polyurethane grout is often used in non-structural water infiltration/inflow related repairs. Our technicians inject polyurethane grout in actively leaking joints, cracks, faults and voids using mechanical packers that are installed by drilling the structure, inserting the packer and tightening. Polyurethane grout is then injected at high pressure. Two types of polyurethane grout are typically used in these applications, hydrophobic and hydrophilic. Hydrophobic grout repels, has high expansion and cures rigid. Hydrophilic absorbs water, has lower expansion and cures to a flexible foam. Both styles require an actively leaking crack as they are water activated. Polyurethane grouting is a common fix in water treatment plants also were tanks with unconsolidated or aging concrete leak.
Epoxy Grout Injection
Epoxy grout injection is also used in the repair of a wide variety of concrete and other structures. Epoxy injection is a bonding process. The material fills cracks and welds them together structurally. Epoxy grout is also pushed through the crack under high pressure and the bond it forms is stronger than the substrate itself. This repair restores structural strength to the cracked concrete and mitigates concrete spall initiated by cracked concrete. Epoxy injection can be used to prevent the corrosion of reinforced steel and to fill voids in unconsolidated concrete.