New building of the Martin-Behaim-Gymnasium

The load-bearing structure of the new building combines timber and reinforced concrete. While the basements and the foundation consist of reinforced concrete, the facade, load-bearing interior walls, and ceilings from the ground floor upwards are executed in timber construction. For the entire substructure, around 14,500 cubic meters of ready-mix concrete are used. Of this, 7,500 cubic meters alone consist of recycled concrete, which is used for the 85-centimeter-thick floor slabs. This concrete conserves primary resources, as it contains professionally processed mineral construction waste as aggregate. The earth-retaining walls were concreted as a waterproof construction, a so-called "Gelbe Wanne" (waterproof concrete structure with a pre-applied bonded waterproofing membrane), using a concrete compressive strength class of C 30/37.

The timber construction is progressing rapidly due to a high degree of prefabrication: almost 100 timber columns, each weighing 470 kilograms, have already been assembled on the ground floor, upon which the downstand beams and timber ceilings rest. The building's energy supply is provided by geothermal probes, for which boreholes and connecting trenches were excavated directly beneath the future floor slab. Another detail in terms of resource conservation: instead of completely clearing the construction site, larger, older existing trees on the premises were professionally transplanted.

In order to logistically process the enormous quantities of material during the structural work efficiently, truck-mounted concrete pumps with a 52-meter boom were used for the concreting, pumping up to 500 cubic meters of the recycled concrete per day directly into the formwork of the solid components.

Text: ZAB | Sources: Martin-Behaim-Gymnasium Nürnberg, Cemex Deutschland, Riedel Bau AG, wbg Nürnberg GmbH