REPAIR OF PCCP BY POST TENSIONING

摘要

The Great Man Made River Authority (GMRA) is in charge to build and operate a major water supply system in Libya. This system includes pumping stations located at the well fields, conveyor pipes and reservoirs. Six phases are scheduled. To date, three phases are in service representing around 4 000 km of pipes. Most of the pipes are 4.20m internal diameter, made of prestressed concrete, prefabricated in 7,5 m long elements. In 1999, GMRA has faced some pipe bursts due to a high corrosive environment. GMRA started immediately pipe inspections and asked Freyssinet to proceed with repair of critical pipes with additional external post tensioning. The first emergency repairs have been carried out using available materials. Since this first repair, GMRA and Freyssinet have cooperated to develop a special technology which gives a long term service and makes the repair as a final solution.