Repair of wooden utility poles using fibre-reinforced polymers

Abstract

All wood utility poles require an effective maintenance program to ensure safe and reliable service. The end of a wood utility pole's useful life can be attributed to several factors including decay, mechanical damage, weathering and changing design circumstances that require the pole to be modified. Pole life can be extend through an effective preservative treatment and maintenance program, but at some point, all poles will reach a point when they are no longer suitable for their intend use. With the increasing cost of quality wood for use in poles, and the environmental concerns regarding pole disposal and chemical treatment of existing poles, new methods are required to restore and maintain wood poles. A research program was initiated at the University of Manitoba's Civil Engineering Composites Facility to develop a repair and restoration technique for wooden poles using fibre-reinforced polymers (FRP) to extend their useful life. Twenty-seven 3050-mm poles were tested as cantilevers under static loading. The experimental results showed that the repair techniques developed for restoring wood poles were successful in restoring fully the original installation strength. The program also included the development of finite element models used to predict the behavior of FRP-rehabilitated utility poles. Equations were also developed to assist in the design of the FRP-repair.