Dyckerhoff CEDUR composite cement rebuilds Lörrach hospital

Dyckerhoff secured an order for the delivery of 68,000m³ of concrete to rebuild the central hospital in Lörrach, southwest Germany. The concrete is produced with Dyckerhoff Cement from the Göllheim and Amöneburg plants. For the duration of the construction period, the Dyckerhoff mobile plants branch operates a mobile mixing plant directly on site.

Approximately 6000m³ of ready-mixed concrete of quality C30/37 in consistency F4 was produced in the mobile plant for the foundations, which are designed as massive components. This concrete was produced with the newly developed Portland composite cement CEDUR from the Dyckerhoff plant in Amöneburg.

Dyckerhoff and the parent company Buzzi Unicem have been working for some time on the development of composite cements with an efficient use of limited raw materials with the lowest possible clinker content. These cements carry the CGreen label. The label appears only on products with a significantly reduced CO₂ load. This includes the particularly CO₂-efficient Portland composite cement CEDUR used in Lörrach with the standard designation CEM II/CM (S-LL) 42.5 N-LA. Compared to pure Portland cement (CEM I), CEDUR contains up to 50 per cent less clinker, which is replaced by limestone and blastfurnace slag.

For the basement rooms CEM II/CM (S-LL) 42.5 N-LA was selected, because of its slow strength development and low heat of hydration. The limitation of the crack width and a low water permeability could be achieved very well with the CEM II/CM cement.

Since May 2022, all other components up to strength class C30/37 have been manufactured with the newly developed Dyckerhoff MZ-V double with the standard designation CEM II/BM (V-LL) 42.5 N (az) from the Göllheim plant. Due to the use of fly ash as the main component and the lower clinker content, this cement has a better ecological balance than the previously used PKZ double (CEM II/A-LL 42.5 N).

The Stetter M 2.5 mobile mixing plant set up in Lörrach has an hourly output of 110m³ of ready-mixed concrete. The three silos (one of which is a double-chamber silo) have a capacity of 300t and enable the processing of up to four types of binding agent. The set-up time between two uses is 14 days.

The construction work for the project began in July 2021, and the shell work should be completed in the summer of 2023. The clinic is scheduled to go into operation in 2025.