Repair of Impact Damaged Utility Poles with Fiber Reinforced Polymers (FRP), Phase II. Final Report 2/27/2014-6/30/2015.

摘要

Vehicle collisions with steel or aluminum utility poles are common occurrences that yield substantial but often repairable damage. This project investigates the use of a fiber-reinforced polymer (FRP) composite system for in situ repair that minimizes potential traffic interruptions. The FRP repair system consists of a filler material to restore a circular crosssection, a primer or adhesive layer, a pre-impregnated or field-impregnated FRP laminate, and a final coating for aesthetics and UV protection. The objective of this study is to develop a set of repair guidelines that can economically and effectively restore an impact-damaged utility pole to a safe working condition. The research plan was divided into three stages. The first stage is a material characterization of the constituents of several likely FRP repair systems, including characterization of the efficacy for installation on vertical poles. The second stage investigates the component-level responses of the repair systems. Mechanical testing to failure was performed for a variety of pole and dent geometries in a standard four-point flexural test setup. The final stage involves verifying the component-level tests using full-scale poles. The poles utilized for testing included both actual poles removed from service with vehicular impact damage as well as poles with mechanically-imparted dents. All full-scale tests were performed on poles with integral base plates oriented in a cantilever configuration and subjected the specimens to flexural monotonic loads to failure, cyclic fatigue loads to failure, and impact loads simulating vehicular impact using a pendulum. Geometric irregularities in the pole and access ports (hand holes) make design of the repair systems challenging. Laminates were oriented in the longitudinal direction on the tension and compression faces with transverse (circumferential) wraps located above and below any obstructions. Results show the repairs to be effective at restoring capacity, resisting cyclic/fatigue load demands, and not prone to instability when impacted with the equivalent of a light vehicle at low speed.