Hebel: Circular building supports new German industry
The future of construction is circular. By advancing circular construction and building cities from cities, Holcim saves primary materials and creates high-value solutions, in this case fully recycled Hebel autoclaved aerated concrete (AAC) panels for a new industrial building in Germany.
With their modular design, structural strength, light weight, excellent thermal performance, and fire resistance, Hebel AAC offers many benefits. Production is even optimized to use more than 60% less embodied energy than standard concrete blocks, while emitting far lower emissions.
In addition, Hebel AAC panels can be fully recycled as construction demolition materials (CDM) for reuse in brand new AAC, as this pioneering project in Puchheim near Munich shows.
Recycling Hebel AAC to build new from old
When a 50-year-old industrial hall made of Hebel AAC reached the end of its operational life, its wall panels were still in good condition. We were therefore able to recycle them for use in a new, larger commercial building designed by Munich architects b_Arch.
We benefit in two ways. On the one hand, we can reduce the proportion of valuable raw materials and the CO2 emissions of our solution. On the other hand, we can meet the demands of our customers, who are specifically looking for sustainable products.
- 225 m3 of Hebel AAC was recycled, creating new AAC for the new building onsite
- Modular Hebel AAC wall panels enhance onsite productivity - for fast, efficient construction with less manual labor
- Hebel AAC acts as a permanent carbon sink, absorbing CO2 via natural recarbonation
No compromise on quality or performance
In total, 225 m3 of old Hebel AAC wall panels onsite were dismantled and strictly separated to ensure material purity – a vital requirement for high-quality recycling. They were then crushed and screened into a high-grade secondary AAC powder, transported to the nearby plant and reintroduced into the production cycle.
Recovered materials were successfully used to substitute primary sand and binders in the new AAC, keeping valuable resources in the value chain and closing the loop.
Even after 50 years, the material’s integrity was uncompromised. The recycled AAC met the same rigorous quality standards as primary AAC, showing how recycled materials can be used to create high-value solutions with no compromise on quality or performance.
Modular building enhances onsite productivity
To construct the new commercial building in Puchheim, modular Hebel wall panels were used to create a 50 meter-long, column-free interior, significantly accelerating the speed and efficiency of the build, and reducing manual labor needs.
Moreover, due to their ultra-porous structure, Hebel panels – in addition to their sustainability benefits on the production side – easily and permanently absorb CO2 from the atmosphere through natural recarbonation, further strengthening their sustainability credentials.
Beyond this project, for some years Hebel AAC has offered a return system, whereby offcuts on construction sites can be returned to the plant, ground and then milled for use in new AAC.
Read how Holcim is expanding in high-value Building Solutions with brands like Hebel. We’re also scaling circular construction in cities worldwide using our ECOCycle technology, as sustainability drives profitable growth through our NextGen Growth 2030 strategy.
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