Pipe Rehabilitation

Freyssinet has drawn from its knowledge in carbon fiber strengthening and in post tensioning to develop a complete offer for rehabilitation of large diameter pipes. Freyssinet has designed two innovative products specific to pipe repair: FREY-CWRAP® and DURALOOP®.

The repair methods are primarily intended for PCCPs (Prestressed Concrete Cylinder Pipes). PCCPs are used for transmission and distribution of drinkable and waste water in municipal, industrial and irrigation networks. PCCP relies on prestressing wires wrapped around a concrete core for structural strength. Corrosion of the prestressing wires leads to pipe shutdowns and the possibility of catastrophic failures.

Application of additional externally applied post-tensioning to compensate the failing prestressing force is a natural idea.

Freyssinet’s PCCP External Durable Pre-grouted PT system, DURALOOP®, is based on the use of Freyssinet’s patented 2MX15 anchorage and special indented strand centering external HDPE/PP sheathing to achieve a fully encapsulated and durable post-tensioning system. Pre-grouting of the centralized strands prior to stressing provides uniform support of the unbonded monostrands, thus ensuring that the corrosion protection system remains intact.

Reinforcement by Carbon Fiber Reinforced Polymer (CFRP) lining is a promising technology for pipe repair. To meet the growing demand for this technology, Freyssinet has developed FREY-CWRAP®: a carbon fiber/epoxy resin composite specifically designed for application on PCCP surfaces. The system has been approved by the NSF for drinking water applications. Freyssinet took the technique one step further by developing the FREY-CWRAP® robot, automated equipment capable of repairing pipes between 60” and 120” in diameter at incomparable speed.

References:

• Go to the Projects section to review the full references list.