Rapid-hardening concrete used for the “Heitersberg Ost” track renewal project

Initial situation

The Heitersberg line is an important section of the east-west connection between Zurich and Bern. SBB will be carrying out various maintenance work on three bridges and the track between Mellingen-Heitersberg and Mägenwil between now and 2025.

The company Concretum was involved in this work to renew the dilatations (roadway crossings) and bridge edges. The removal of the tracks, the new laying and the concreting had to be carried out during eight weekend closures so that the railroad could resume traffic on time the next day.

Solution and assessment

The track work was carried out in summer 2023. Particular attention was paid to allowing the concrete to harden quickly so that all subsequent work steps, such as the renewal of the expansion joints, could be carried out on schedule.

To ensure that the specified schedule was adhered to, Concretum^® Q-Flash 2/20 rapid-hardening concrete was used, which was produced in a truck mixer in collaboration with the Hubschmid company.

The specified open time of the concrete enabled safe delivery from the production site to the installation site, and sufficient time was available to place and process the concrete.

Approximately one hour after the end of the open time, the rapid-hardening concrete had sufficient strength for the next work steps, allowing the roadway to be reopened to traffic in good time.