Fiber Reinforced Polymer Composite Utility Poles
PROJECTS OF CFC - FIBER REINFORCED POLYMER COMPOSITE UTILITY POLES
Wood poles have been used for many decades because of availability, low cost and insulating nature, and have been functionally more than satisfactory with a service life of about 30 years. The wood poles are initially surface-treated with toxic chemicals (creosote, copper chromium arsenate or penta-chloro-phenol) to resist rot, decay, insects, microorganisms and woodpeckers, and maintenance must be continued throughout the service life with regular in-situ surface retreatment. Harmful chemicals are carried into the storm water run-off and eventually enter into the groundwater because of chemical leeching, resulting in a significant negative impact on the environment. This environmental concern has already caused increases in surface treatment costs of wood poles and made disposal of used wood poles very expensive, and is leading to potential elimination of chemical preservatives. In addition to environmental hazards of chemical treatment, long and straight wood poles are becoming more difficult to obtain and more expensive due to dearth of quality wood of lengths ranging from 40-80 feet. Steel poles have some advantages over wood poles such as longer service life (60-80 years), lighter weight, higher stiffness and lower maintenance. However, their application is limited to certain conditions. Steel distribution poles are conductive, difficult to repair and harder to field drill.
Limitations of conventional constructional material usage have led to an increase of interest in fiber reinforced polymer poles from electrical utilities and communication companies. Such interest is attributed to their strength, durability, safety and cost-effectiveness.
FRP poles appear very promising to fulfill the environmental and structural criteria, life expectancy, cost requirements and recyclability. Utility companies are slowly beginning to use FRP poles for niche applications, such as in mountainous terrain where light weight installations is an important benefit or in soils where non-corrosive properties of composites are a major advantage. Such restrictive use of FRP poles has come about because they are less economical than wood poles, typically two-three times the cost of wood poles and because of the absence of design and construction specifications.
One of major research activities at the Constructed Facility Center deals with the development, application, field implementation and response evaluation of FRP utility poles. We are conducting research and development of new generation FRP poles through the advancement of composite pole technology by incorporating a number of recent technological innovations developed at the CFC. The objective is to mass-produce FRP poles through a pultrusion process with an optimal product design and process improvements in lieu of creosote-treated wood poles to meet the power industry's requirements at competitive prices and improve the nation's highway safety with more ductile utility poles as safer roadsides. The proposed FRP poles will have higher strength- and stiffness-to-weight ratios, better impact energy absorption and durability, improved design and manufacturing flexibility, higher energy efficiency in production, and safer environmental characteristics and will be more economical than the existing steel or concrete poles, or even with respect to the existing FRP poles.