When it comes to the construction and transportation industries, polyurethane is one of the most versatile and flexible materials in the world. In its various forms, polyurethane has many applications from coatings, sealants, and adhesives to void filling, structural support, and insulation. As such, polyurethane’s use within the construction industry has steadily grown especially in sewer infrastructure repair projects.
What is Polyurethane’s Role in Sewer Infrastructure Repair?
In sewer infrastructure repair, polyurethane has several useful applications. Polyurethane foam can be used to treat inflow and infiltration issues in manholes, pipe joints, laterals, culverts, and outfalls. It can also seal off and prevent water intrusion to utility boxes, wet wells, and pump stations. Hydrophobic polyurethanes perform exceptionally well in wet conditions, making it the perfect choice for these types of repairs.
Using polyurethane for infrastructure repair has many benefits. The material is lightweight, affordable, and fast curing. Despite its lightweight, this closed-cell foam has strong structural properties. It’s also minimally invasive and environmentally inert. Polyurethane repair projects require zero-excavation, which results in a small project footprint.
How Does it Work?
Polyurethane foam is created with a two-part solution. Part A is a chemical called MDI, or Methylene Diphenyl Diisocyanate (also known as ISO) while Part B is resin, a combination of polyols, catalysts, blowing agents, and other components. The two-part solution is mixed using an impingement gun and injected into voids around the affected asset. Tubes can be used to inject the polyurethane into particularly deep or large voids, or otherwise inaccessible areas.
Once the polyurethane is injected, it begins to expand to fill the void and compact unconsolidated soils around the infrastructure asset. The polyurethane will follow the path of least resistance to fill and compact soils. As it does so, it will press against the asset, creating a tight seal and blocking off any cracks or other openings that could allow for water and soil to infiltrate. Due to its hydrophobic properties, the polyurethane will displace any water that surrounded the asset, ensuring a dry environment and preventing damage from moisture.
Polyurethane is a fast-curing material, which means these types of infrastructure repairs can occur quickly. After injection and expansion, any excess foam is trimmed away to prevent any future blockages within the pipe and the small injection site holes will be filled.
With its structural stability, water-repelling qualities, fast cure time, and small project footprint, polyurethane foam makes for a reliable solution to infrastructure repair.
