DURABILITY OF SPECIAL COATINGS FOR CORRUGATED STEEL PIPE

The report covers a literature search and review and a limited field study to update previous work related to corrugated steel pipe (CSP) and durability estimation (expected service life). The study, using plain galvanized (zinc coated) CSP as the base line, addresses additional coatings including nonmetallic (bituminous coated, bituminous coated and paved, polymers, fiber bonded, epoxy bonded and concrete lined) and other metallic coatings (aluminum-zinc (galvalume) and aluminum-coated type 2) that may be used to achieve a desired design life of at least 50 years. The study is limited to storm drainage systems carrying naturally occurring surface water only. The recommendations in the report do not apply to sanitary or industrial sewers or other conduits used to carry corrosive effluents. The information collected in the study revealed that with additional coatings such as bituminous coated and paved, polymer coated (ethylene acrylic acid film) or concrete lined, under proper conditions, the expected service life of galvanized CSP can be extended to at least 50 years.