Corrosion Protection for Bonded Internal Tendons in Precast Segmental Construction

This report documents a series of accelerated corrosion tests on small-sized specimens typical of bonded internal post-tensioning tendons in segmentally constructed box girder concrete bridges. Thirty-eight macrocell specimens were subjected to a highly aggressive exposure and observed for four and one-half years. At that time, nineteen of the joint type (dry or epoxy), duct type (galvanized steel or plastic), grout type (3 grouts with different additives) and level of joint compression (3 different levels). Half-cell potentials and macrocell corrosion currents were measured throughout exposure. While some substantial corrosion was found in dry joint specimens, the corrosion resistance of epoxy joint specimens was excellent.