Corrosion characteristics of unprotected post-tensioning strands under stress.

PDFTech ReportBDK84-977-22Corrosion protectionPosttensioningReinforced concretePiles (Supports)Tensile strengthBend testsReinforcing steelRustingTendons (Materials)FloridaFlorida. Dept. of TransportationFernandez, JosephHutchison, MichaelSag\uc3\ubc\uc3\ua9s, Alberto A.Mullins, GrayUniversity of South Florida. Dept. of Civil and Environmental EngineeringUS Transportation CollectionAn investigation was conducted to determine the effect of stress conditionand environmental exposure on corrosion of post-tensioned strands during ungrouted periods.Exposures for periods of up to 4 weeks of stressed, as-received strand placed in tendon ductsembedded in concrete and sealed with caps to represent normal practice and without anytrapped water did not result in any appreciable deterioration as evaluated by visualappearance, standardized mechanical tensile testing, limited reverse bend testing, andexploratory hydrogen pickup measurements. These results were observed at both an inlandand a seashore test site. There was, however, notable surface rusting and indications ofhydrogen pickup by the strand if water was trapped in the ducts or if the steel was exposed tomoderate salt spray precipitation and especially so with both factors concurrently. Evaluationof significance of findings on current practice is presented