As part of the work to upgrade and renovate the water mains and sewer network for Canal Isabel II, Madrid's water company, ACCIONA has repaired one of the city's largest water main, Arteria Principal del Este, using an innovative system consisting of building a new carbon fibre pipe in situ inside the existing pipe.
The technique enables water mains to be upgraded without any need for digging, which greatly reduces traffic disruptions and other nuisances such as noise and vapours from conventional cutting and welding operations.
The system also reduces water supply cuts by halving the time taken to repair a pipe. The environmental impact is also lower since no heavy machinery is required.
In technical and functional terms, the carbon fibre pipe has better mechanical properties (strength, durability, etc.) than the pre-existing pipe and it has an estimated useful life of over 40 years.
ACCIONA is in charge of upgrading and repairing the water mains and treated water network for Canal de Isabel II in the cities of Alcobendas, San Sebastian de los Reyes, Tres Cantos and San Agustín de Guadalix, as well as the area of Madrid itself between the A2 (Barcelona road) and the A6 (La Coruña road).
The new technique is part of the company's preventive maintenance work. An internal inspection of the main revealed a number of structural anomalies which, though not affecting performance as yet, would need to be remedied to avoid failures or leaks in the future.
Nine non-contiguous sections of pipe that were susceptible to breakage were identified. A total of 76 metres of pipe were upgraded. The resulting pipe, on its own, is able to withstand service pressure and the burdens to which it will be subjected while the old pipe, though remaining in place, does not contribute any additional strength.