Post-tensioned segmental box girder bridges have typically relied on cementitious grouts to provide corrosion protection for pre-stressing steel. Several notable incidents involving corrosion damage o..
Post-tensioned segmental box girder bridges have typically relied on cementitious grouts to provide corrosion protection for pre-stressing steel. Several notable incidents involving corrosion damage over the past 20 years have led the Florida DOT to adopt flexible fillers as a substitute for cementitious grouts. The purpose of this research is to explore non-destructive evaluation techniques to guarantee that post-tensioning steel ducts containing flexible filler are not experiencing corrosion. To use these fillers in bridge design it is important to verify the evaluation techniques available can ensure the fillers are compatible with these bridges and improve the overall design life. The first phase of this study has focused on a survey of the existing literature. There have been no breakthroughs in determining the best methods for evaluating post-tensioning ducts with cementitious grouts or flexible fillers. The next two stages will be more in depth to determine the best methods for inspectors to deploy in the field. This literature review examines a few methods for the inspection of flexible fillers. Visual indicators allow for the identification of areas of interest which can then be later inspected with either magnetic flux leakage or ultrasonic testing. Magnetic flux leakage allows for the detection of corrosion within the strands contained in the PT duct. Ultrasonic testing allows for the identification of high material stresses at the end caps of the PT system. The continuation of the research will focus on the application of these methods and others to routine biannual bridge inspections of flexible-filler bridges. Keywords: Post-Tensioned, Bridges, Flexible Fillers, Corrosion, Non-Destructive Evaluation, Magnetic Flux Leakage, Ultrasonic Testing, Visual Indicators