RÄNGGLOCH

OBJECTIVE

As part of a comprehensive renovation of the Kanton road 4 between Littau and Kriens, the Ränggloch Leaning Viaduct was constructed to enhance traffic safety, improve cycling infrastructure, and strengthen protection against natural hazards. A key focus of the project was to explore innovative, durable materials in bridge post-tensioning—specifically, to test the real-world application of carbon fibre-reinforced polymer (CFRP) tendons.

SOLUTION

To achieve this, two of the four conventional 12-strand steel tendons in the end span of the viaduct were replaced with parallel wire bundles made from CFRP, each consisting of 91 individual 5 mm CFRP strands. For the first time worldwide, these tendons were anchored using end terminations made entirely of CFRP. This innovative system, designed and supplied by Carbo-Link, allowed for corrosion-free, unbonded installation and enabled permanent force monitoring via load cells. Extensive testing, including bending and long-term creep experiments, validated the system’s structural integrity and performance.

DELIVERED

2 parallel wire bundles: Each cable weighs just 2.75 kg/m despite incorporating 91 wires and has an installed length of 25 m, equating to 2,275 m of carbon fibre per tendon.

2 end terminations: The tapered anchor sleeves measure 700 mm in length, 250 mm in outer diameter, and weigh only 14.5 kg.