The Largest, Single Source Provider of Bonded Post-Tensioning System Components Home » Post-Tensioning » Bonded Post-Tensioning » GTI Bonded Anchorages » GTI Flat Anchorages GTI Flat Anchorages For bonded tendon applications on thin concrete sections the GTI Flat Anchorage is ideal. It can be used for both 0.5” and 0.6” strand sizes, is simple to install and mates perfectly with GTI Flat/Oval Corrugated Plastic Duct. GTI S-4-05/06 Anchorage