Aluminum‐Coated Corrugated Steel‐Pipe Field Performance

Abstract

The design life used by many agencies for planning drainage structures has increased to 50 years or more in recent years. This has created a niche for a more durable product in the low‐cost market. Aluminum‐coated corrugated steel pipe (CSP) is one contender for this niche. The Federal Highway Administration (FHWA) has aluminum‐coated CSP field test sites that have been monitored since their installation in 1981. To date, however, monitoring has consisted primarily of visual inspections. The objective of this study was to quantitatively document the performance of the FHWA installations in terms of site conditions and in comparison with adjacent galvanized and aluminum‐zinc‐coated CSP culverts. Culvert deterioration was evaluated by measuring the maximum pit depth in the metal samples taken from pipe inverts. The conclusions of this study are limited by the small size of the data set and the young age of the data. However, during the first seven years of exposure, the aluminum‐coated CSP studied performed an average of over six times better than the California method predicts for plain galvanized at the 14 sites investigated.