Renewal of the Fixed Railway Track in Zurich Airport Station by Means of Blocks in UHPFRC

Abstract

This contribution presents a probably worldwide first application of UHPFRC for the renewal of an existing fixed railway track in a heavily trafficked underground railway station. The existing fixed railway track of the Zurich Airport train station was constructed in 1980. It consists of four 640 m (700 yards) long tracks constructed as slabs in concrete. According to the state-oftechnology at that time, the fixed railway track was built as a reinforced concrete slab and prefabricated monoblocs of the LVT L77-B type (Low Vibration Track), which were fixed by unreinforced concrete casted on top of the reinforced concrete slab. Already after a few years of operation, first cracks were detected in the monoblocs, and after 30 years of operation, significant damage in terms of cracking and fracture of monoblocs was detected, making the replacement of the blocks necessary. The use of UHPFRC allowed to reduce significantly the monobloc size and to accommodate for new requirements regarding the height of the platform, avoiding costly construction interventions, thus leading to a reduction of overall construction cost by 30% compared to traditional renewal methods using concrete. The use of UHPFRC and novel technologies allowed to improve the existing fixed railway track in terms of fatigue resistance and to increase the service duration to a very long service duration. The paper presents the design of the UHPFRC pedestals, and the execution of works including quality control.