BBR VT CONA CMB band post-tensioning system
The European approved CONA® CMB post-tensioning system is a multi-strand technology for special external and also internal unbonded post-tensioned applications. The standard tendon configurations range from 1 to 16 strands. The unique system design offers a high level of corrosion protection and is widely used for the prestressing of wind towers but also for strengthening of railway and road bridges.
The double-extruded CONA CMB band technology is restressable and exchangeable, and mostly prefabricated and rolled onto drums that allows swift installation of tendons.
The main components in the anchor zone of the CONA CMB system are the wedges, anchor head, load transfer element and trumpet. For the load transfer to the concrete, the CONA CMB SP (square plate) is used allowing for quick and simple installation.
The CONA CMB band offers a unique flat band bundle that permits simplified deviator/saddle design and tendon installation compared to the more traditional round external post-tensioning duct.
The strands are greased/waxed and individually sheathed in a factory with a continuously extruded HDPE sheathing and subsequently grouped parallel and then contained within an optional additional extruded smooth rectangular plastic sheath forming flat bands of strands.