Over the past few years, a new small-diameter pipe has been developed for storm water drainage, culverts, and similar applications. The product is manufactured from polymer-coated galvanized steel by the helical lock seam process on a new line of equipment developed for that purpose. Known as PolyRib pipe, the profile is composed of sets of three closely spaced ribs with a wider spacing between the sets of ribs to accommodate the lock seam. As part of the process for evaluating the new product, tests were conducted that included hydraulic tests, soil box tests, installation tests, pipe stiffness tests, beam tests, and durability tests. The results of these investigations are summarized. New ASTM standards may be used to design and specify the product. Procedures for determining sectional properties and a table of maximum fill heights have also been developed. Evaluation of the information shows that the product has the required attributes to provide a competitive new drainage pipe for moderate fill heights in the small-diameter market.
Abstract