Durability Testing of Composite Materials for Reclamation Pipelines
The purpose of this study is to determine durability testing and quality assurance methods to facilitate use of
composite materials on Reclamation pipeline projects. Laboratory durability testing would aid Reclamation staff in
developing performance standards during the pipeline design phase. Quality assurance methods would be used by
field personnel during installation to ensure a quality product is delivered. This research would primarily be
directed toward use of fiberglass pipe and fittings, but would also be extended to tanks and structural
components (vaults, manholes, etc.).
Need and Benefit
Fiberglass pipe is typically more expensive than other pipe options (concrete, steel, and PVC) but has higher
strength values and excellent chemical resistance. Therefore, fiberglass pipe is cost competitive in high-pressure,
large-diameter applications, requiring increased chemical resistance. Composite pipe often has lower installation
costs than steel or concrete pipe due to its lower weight, which can make it a cost-competitive option from an
overall project perspective. In addition, composite pipe is a corrosion resistant alternative to steel pipe, offering
superior performance in certain soil environments and design situations.
In the 1980's, Reclamation had a series of pipe failures with RPM (Reinforced Plastic Mortar) pipe in diameters
ranging from 24- to 48-inches. Pipes were typically buried in the right-of-way on rural roads. Failures were
catastrophic (pipe burst) leading to significant concerns to public safety. Reclamation placed a moratorium on RPM
pipe while the reasons for premature pipe failure were investigated. Reclamation concluded that the
manufacturing process was highly variable. The glass fibers were wrapped around a steel mandrel and alternated
with layers of resin and sand filler. The RPM pipe was subject to manufacturing flaws because each pipe section
was essentially fabricated by hand and highly dependent on the skill of the manufacturing technician. The hand
lay-up process also resulted in resin voids within the pipe wall profile. These voids made the RPM pipe highly
sensitive to construction impact damage – far more sensitive than other pipe options.
Recent advances in composite pipe technology seem to have addressed the previous concerns with RPM pipe.
Modern composite pipe is centrifugally-cast using chopped or continuous fibers. Manufacturing is computer
controlled resulting in a consistent product. The centrifugal cast process results in a dense pipe wall with
complete resin saturation of the glass and sand filler. This project aims to investigate the current composite pipe
products via in-house testing in the above-mentioned challenge areas. In addition, quality assurance procedures
will be developed to evaluate as-received pipe in the field. This research could make available an economically
competitive class of pipe with superior corrosion resistance that is currently not considered for Reclamation
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Durability Testing of Composite Materials for Reclamation Pipelines (final, PDF, 1.6MB)
By Jay Swihart
Publication completed on May 01, 2016
Durability Testing of Fiberglass Pipe for Reclamation Pipelines (final, PDF, 4.3MB)
By Kelly Ramaeker and Michael T. Walsh
Report completed on September 30, 2018