Comparison of Spray-On Linings for Water Pipeline Renewal Applications

There is no doubt that pipeline systems, in general, and potable water pipelines, specifically, form an important part of our infrastructure. These pipelines constitute a large and complex system that has been expanded and developed during the last century. Usually, signs of wear and failure for underground infrastructure - such as water transmission and distribution systems- are not apparent until a major leak or collapse is found. This commonly leads to emergency repairs, which may cost 10 times more than planned repairs and may result in the loss of millions of gallons of treated water, as well as inconveniences to consumers and the general public. Specifically, the existing cast iron pipes have become corroded over time, both internally and externally, resulting in water loss through holes and cracks, and water quality and hydraulic capacity problems. Spray-on lining methods have effectively been used to renew deteriorated water pipelines for more than 20 years. Depending on the method and product used, these liners can potentially eliminate most of these problems. This paper provides a comparison of spray-on lining methods - including cement mortar, epoxy, polyurethane, and polyurea linings - and an overview of their advantages and limitations. It also provides the physical properties of different lining materials available in the market. Additionally, long-term testing plans and equipment for tensile, flexural, and internal pressure are described.