Evaluation of Corrugated HDPE Pipes Manufactured with Recycled Content

Abstract

The objective of the research project was to compare the performance of corrugated high-density polyethylene (HDPE) pipes manufactured with recycled content to those manufactured with only virgin materials. MnDOT currently requires HDPE pipes to be made with 100% virgin materials. However, recent changes to American Association State Highway and Transportation Officials (AASHTO) M 294 include the option for pipes manufactured with post-consumer and post-industrial recycled content, both of which have been shown to be more sustainable materials than virgin HDPE. The research project involved the installation of two 36-in. diameter corrugated HDPE pipes - one manufactured with 100% virgin materials and the other with a blend of virgin and post-consumer recycled materials - underneath a roadway near Fosston, MN. A life-cycle assessment was conducted to compare the environmental impact of the virgin pipe with the pipe manufactured with recycled content, and a cost analysis was conducted to estimate the cost savings of incorporating pipes manufactured with recycled content to the state of Minnesota. The research project showed that the virgin and recycled pipes are performing comparably and that the pipes manufactured with recycled content offer significant environmental benefits and potential cost savings. Due to installation and measurement issues, both the virgin and recycled pipes appear to be deflected beyond MnDOT requirements, and it is recommended that they continue to be monitored.