Everything cast in one piece in 18 hours: Riedberg tunnel portal

After eight years of construction, the two 500-metre-long tunnels through the Riedberg are due to open at the end of 2024. The A9 structure serves as a bypass at the Gampel/Steg railroad station bottleneck. The Volken Group recently completed the first portal block together with ARGE Tunnel Riedberg - in just 18 hours, using 372 m3 of concrete from powerful truck mixers, a 36 m truck-mounted concrete pump and other heavy equipment. The challenge here was to reduce the formwork pressure due to the immense component thickness and to complete the portal in a single pour.