Replacement of the SBB Bridge on Usterstrasse, Wetzikon

In summer 2026, the more than 100-year-old railway bridge over Usterstrasse in Wetzikon was replaced by a new structure. The existing steel bridge was in poor condition and no longer met future requirements. At the same time, the replacement creates the necessary conditions for widening Usterstrasse and thereby improving safety for cyclists and pedestrians.

A significant part of the construction work was carried out during a three-week complete closure of the railway line. Completing the works within this tight time frame placed high demands on planning, coordination and logistics. Thanks to a high degree of prefabrication, the existing bridge could be dismantled, the railway embankment removed and around 120 metres of bored piles installed during the closure, more than half of them in hard rock. The abutments were then constructed and the steel superstructure installed using Switzerland’s largest crawler crane. The required concrete works also had to be completed within the specified schedule

Challenge

The complete closure of the railway line provided a clearly defined and tight time frame for all construction activities. The individual work stages were directly dependent on one another and had to be precisely coordinated to ensure that subsequent works could proceed without delays. The concrete works for the piles, abutment and wing walls of the new bridge were particularly critical. A concrete solution was required that provided sufficient workability time for production, transport and placement while also achieving the required strength rapidly. This was essential to ensure that the subsequent works could continue as planned within the tightly scheduled construction programme.

Solution

The Concretum^® Q-FLASH 5/20 rapid hardening concrete system was used for the concreting of the piles, while the Concretum^® Q-FLASH 2/20 rapid hardening concrete system was used for the abutment and wing walls. A total of approximately 62 m³ of rapid hardening concrete was produced at the Ebirec concrete plant of Eberhard Bau AG and placed on site. The concrete’s workability time was specifically adapted to the conditions and construction sequence on site. At the same time, its rapid strength development ensured that subsequent works could continue without long waiting periods. This allowed the concrete works to be reliably integrated into the tightly scheduled construction programme.

Result

The concrete works for the piles, abutment and wing walls were successfully completed within the specified time frame. Through the coordinated interaction of concrete production, site logistics and rapid strength development, the subsequent construction stages were able to proceed as planned. The works carried out during the complete closure were completed on schedule, and the railway line was reopened as planned.

The Wetzikon project demonstrates how rapid concrete can contribute to the reliable execution of larger-scale concrete works within short closure periods, even in demanding infrastructure projects.