Comparative evaluation of inspection techniques for impregnated wood utility poles: ultrasonic, drill-resistive, and CT-scanning assessments

摘要

Above-ground Norway spruce telecommunication poles impregnated with creosote in 1965 were subjected to regular in situ inspection near the end of their service-life in 2013 using also ultrasonic (Fakopp Ultrasonic Timer) and drill-resistance (Resistograph IML-Resi-F-400) techniques. The 1.2 m-long bottom parts of five poles proposed for exchange underwent more detailed in vitro analyses using ultrasonic, drill-resistive and computed tomography (Philips Brilliance CT) techniques followed by visualization of their 11 cut sections. All analyses showed that the most significant decays in poles occurred between the two mounting holes provided to secure the pole to the steel-concrete footings using steel bolts. Observations made by the ultrasonic, drill-resistive and CT techniques and final visualization of the cut sections yielded significant correspondence. In conditioned poles, the CT well identified moderate, severe and very severe degrees of bio-attacks, however it was not the best in detecting slight bio-damages.