Structural Retrofitting of Deteriorated Concrete Lighting Poles Using FRP Sheets in Wet Layup—Field Application

Abstract

This paper investigates the structural retrofit of deteriorated reinforced concrete lighting poles using wet layup of fiber reinforced polymer (FRP) sheets. The study comprised of four full-scale Class B damaged poles and one full-scale Class C undamaged pole. Each pole was 14,000 mm long with a base diameter of 350 mm linearly tapered to a tip diameter of 165 mm. The damaged poles were reinforced with nine No. 10 steel bars each, whereas the undamaged pole had four prestressed steel strands of 3/8 in. (9.5 mm) diameter. Four different in situ applicable repair schemes, one for each damaged pole, involving the application of E-glass or carbon FRP lateral confining wraps only (unidirectional) or coupled with additional longitudinal flexure sheets (bidirectional) were investigated. The adequacy of the retrofit works was checked through full-scale bending test of the poles in accordance with specification of the Canadian Standard Association. All four repaired poles exceeded the CSA design transverse loading requirement for Class B poles. In addition, the bidirectional E-glass and carbon FRP repaired poles exceeded the benchmark performance of the undamaged Class C pole as a percentage of the required design load with the E-glass pole exhibiting the best performance.