Corrosion Protection for Bonded Internal Tendons in Precast Segmental211 Construction

摘要

This report documents a series of accelerated corrosion tests on small-sized211u001especimens typical of bonded internal post-tensioning tendons in segmentally 211u001econstructed box girder concrete bridges. Thirty-eight macrocell specimens were 211u001esubjected to a highly aggressive exposure and observed for four and one-half 211u001eyears. At that time, nineteen of the specimens were opened for detailed 211u001eexamination and all corrosion behavior recorded. The variables included were 211u001ejoint type (dry or epoxy), duct type (galvanized steel or plastic), grout type (3 211u001egrouts with differing additives) and level of joint compression (3 different 211u001elevels). Half-cell potentials and macrocell corrosion currents were measured 211u001ethroughout exposure. While some substantial corrosion was found in dry joint 211u001especimens, the corrosion resistance of epoxy joint specimens was excellent.