HDPE or metal corrugated duct for bonded and unbonded post-tensioning tendons, tested for leak-tightness to EN 523 and fib requirements.
Corrugated duct forms the conduit for post-tensioning tendons in prestressed concrete bridges, buildings and tanks. Plastic (HDPE/PP) duct provides a fully sealed, electrically insulating path, while metal duct is used where higher mechanical protection is required.
The corrugated profile gives high flexibility for curved tendon layouts while resisting crushing under concrete pressure. In bonded systems the duct is filled with cementitious grout after stressing, transferring bond and giving corrosion protection to the strand.