Special formwork for hydraulic tunnel lining with application of HDPE membrane

To meet the growing necessity of the metropolitan and touristic area of Abu Dhabi, during the year 2008 ADSSC has started the STEP project (Strategic Tunnel Enhancement Programme), which will be completed in the year 2015. For the two key parts of the project T-02 (15 km 5.0 m final diameter tunnel) and T-03 (10.5 km 5.5 m final diameter tunnel) both awarded to the contractor Impregilo S. p. A., CIFA has designed and constructed 12 special tunnel steel forms for the loading and traction of the special membrane HDPE (High Density PolyEthylene). This membrane shall be installed before the pouring and integrated with the final lining surface, which has to guarantee over 80 years of useful life of the project under extremely heavy conditions of corrosion. The steel forms shall be used in two equipment units of 12 m for each one of the 6 working fronts of T-02. The keeping of the times for the different working fronts has required the supply of 20 concrete agitators CIFA TRAINMIX of 10 cu.m., as well as 7 portable concrete pumps CIFA CP506/309/E6 on bogie.