A structural high-build polyurethane lining developed by Sprayroq was evaluated by University of Texas at Arlington researchers in the creation of testing and application standards for spray-applied pipe rehabilitation liners in U.S. Department of Transportation markets. The capacity of the SprayWall polymeric material and a cementitious spray-applied liner to renew deteriorated gravity storm conduits was studied and compared.

Both materials were applied to invert-less corrugated metal pipe culverts, designed to simulate deteriorated pipes that failed at the invert, where ring compression forces are the strongest. The control pipe, with no spray-applied treatment, was not able to resist the applied pressure from the test on its own. When treated with SprayWall, the pipe’s load-carrying capacity was increased by 471.7% at 250 mils of application, 484.8% at 500 mils of application, and 802.7% at 1000 mils of application.

SprayWall proved approximately four times stronger than the cementitious mixture when it came to ring compression forces and cured much faster. The cementitious liner required filling in the corrugations of the test pipes in order for it to work properly. In contrast, SprayWall could be applied directly onto the conduits without filling the gaps, potentially saving construction crews time in the field.

As the polymeric spray-applied pipe rehabilitation liner did not crack at the invert-cut location, the researchers concluded that this liner was structurally capable to perform as a new pipe inside the host pipe and could solely resist the applied ring compression.

To contact the author of this article, email shimmelstein@globalspec.com