Abstract Manager

Corrosion of bonded post-tensioning (PT) can proceed with no externally visible signs of concrete deterioration until significant section-loss has occurred, which can seriously affect the structural capacity of the element.  PT corrosion is typically caused by grouting defects, such as voids and soft grout.  Grouting defects cannot be detected through normal bridge inspection methods like visual or tactile inspection methods because the PT strands are encased within plastic or metal ducts and are often embedded within slabs or walls.  VCS has effectively used impact echo/pulse velocity (IE/PV) testing to locate grouting defects in both internal and external PT tendons on structures throughout the world.  This presentation will discuss IE/PV testing together with verification openings performed on bridges with bonded PT throughout North America, including Canadian structures.  Examples will include bridges with both significant voiding and soft grout issues as well as structures in generally good condition.  In addition, the presentation will discuss effective preservation techniques that are used on bonded PT to mitigate the identified damage.