Modelling and predicting the generation of post-demolition autoclaved aerated concrete (AAC) volumes in Germany until 2050

Abstract

Autoclaved aerated concrete (AAC) has a porous structure and excellent thermal properties. Therefore, it is a frequently used building material for masonry units, prefabricated reinforced components and lightweight mineral insulation boards with increasing popularity. Post-demolition AAC is currently mainly disposed of in landfills. Decreasing landfill capacities, the legal framework, and protection of primary resources require developing recycling options for AAC. However, so far, no overall recycling of post-demolition AAC has been established yet. Only AAC primary process waste is recirculated or discharged, for example as an absorbent for chemicals or animal bedding. For high-quality post-demolition AAC recycling, only minimal information about recyclable volumes and their regional distribution is available. Therefore, a new dynamic retrospective and prospective AAC quantification model on a national level using AAC production, construction activity, AAC popularity, and buildings’ lifetimes is developed to assess geographically distributed current and future post-demolition AAC volumes. This new model is applied to quantify post-demolition AAC volumes in a case study for Germany in the period between 1950 and 2050. For validation, the results are compared with two different approaches and with data from the literature. The AAC quantification allows decision support for the circular management of AAC during its life cycle and along its value/supply chain regarding design, location planning, logistics, production, and recycling.