A development that could set new standards in the recycling of mineral construction waste: Etex and Heidelberg Materials have announced a partnership to establish a closed material loop for fiber cement. The model provides for production residues and offcuts from Etex's fiber cement manufacturing to be used in the future as secondary raw material in cement production at Heidelberg Materials. Fiber cement consists of 85–90% cement, water and additives, as well as 10–15% synthetic or cellulose-containing fibers for reinforcement. Previously, production waste was either deposited or thermally recycled – a practice that is increasingly coming under pressure both economically and ecologically.
The partnership is based on a closed-loop model: material residues from Etex's board production are pre-treated to remove contaminants and then fed into the cement production process at Heidelberg Materials. There, the recycled fiber cement particles serve as part of the raw meal mixture or as an alternative calcium source in the rotary kiln. This recycling replaces primary raw materials such as limestone or marl and reduces the need for landfill volume. At the same time, the CO₂ balance of both companies is improved, as fewer primary raw materials need to be extracted and transported. Fiber cement recycling is thus a building block for reducing the clinker factor and improving the EPD data of cement products.
For planners and buyers in the construction sector, the initiative is relevant for several reasons: First, it shows that even mineral composite materials with a fiber content – long considered difficult to recycle – can be integrated into industrial circular processes. Second, this sets a precedent for other material flows, such as insulation materials with mineral binders or gypsum boards with reinforcing fibers. Third, the cooperation is a signal to the supply industry: manufacturers of building materials will increasingly be evaluated in the future on whether they can integrate recycled building materials into their supply chains.
From an economic perspective, the model is attractive for both Etex and Heidelberg Materials. Etex saves landfill costs and improves the environmental balance of its facade boards – an important argument for ESG-oriented building owners. Heidelberg Materials benefits from secured secondary raw materials and can further reduce the CO₂ intensity of its cements, which increasingly becomes a competitive advantage in light of CBAM requirements and national climate targets. The initiative also fits into the context of the circular economy as required by the EU Taxonomy and German federal funding for efficient buildings.
The closed-loop model could serve as a model for further cooperation between building material manufacturers and cement producers. Comparable approaches are known, for example, from the recycling of concrete crusher sand or the return of gypsum waste. For the construction waste recycling industry, this development opens up new business opportunities: processors and recycling centers could act as intermediaries providing sorted fiber cement fractions from demolition and production waste. The key question will be whether the model can be scaled economically with post-consumer waste – a question that depends on logistics costs, processing technology, and regulatory frameworks.
