February - 2019

ACCIONA AGUA was awarded the contract for urgent renovation and repair work in the water supply and reclaimed water networks of Canal de Isabel II Gestión, S.A. in 2017. Amongst the work carried out in the servicing of this contract was the repair of the Main Eastern Artery of the supply network. This repair work was undertaken using an onsite carbon fibre pipe manufacturing system.

The work was carried out on a prestressed concrete pipe of 1600 mm in nominal diameter with a sheet-metal jacket and service pressures of between 9 and 15 bar. This pipeline acts as a
distribution ring for the city of Madrid.

Prior to commencing the repair operation, an internal inspection was undertaken to check the condition of the pipe. A number of anomalies were identified that affected the structure of the pipe and these had to be corrected to prevent potential failures or breakages. This work falls within the framework of preventive maintenance required for this type of water main.

As a result of the inspection, 9 sections were selected in which the condition of the reinforcing frame indicated susceptibility to breakage. Because the pipes affected were not consecutive, the option of replacing them by traditional methods was ruled out and possible options for their replacement or renovation by alternative methods were studied.

In this case, it was decided to implement onsite manufacturing of a carbon fibre pipe using epoxy resin and vacuum consolidation technology. This system enables a new pipe of the same or better properties than the original pipe to be obtained from the interior without the need for any civil engineering work.