This research report was produced in collaboration between Baukreisel, Bauhaus Erde, and Experimental as part of the Experimental Fellowship Program. The focus is on a holistic approach to concrete: the necessity of preserving existing concrete structures, the management of concrete as a waste material, and its circular potential. This potential is explored experimentally through product-based strategies for reuse. Concrete is one of the most defining construction materials of our time. It enabled an unprecedented building boom and gave rise to new architectural expressions. At the same time, the environmental consequences of this development are undeniable. In the face of climate change, the demands for sustainability and resource efficiency—particularly in concrete construction—are increasing. Despite its significant ecological footprint, concrete is often perceived as a short-lived, linear material. This obscures the qualities that originally made it so valuable: durability, formability, and structural performance. Against this background, the question arises: Why concrete matters? The most effective strategy for preserving these qualities and the embodied gray energy in the material is building in place. When deconstruction is unavoidable, the reuse of concrete structures presents substantial ecological and constructive opportunities. This leads to the next question: Why reuse matters? Although concrete reuse has been studied for over four decades and its considerable CO₂ savings potential is well documented, it has seen little implementation in construction practice. So why is this approach not applied on a large scale? How to make it matter more? To scale up reuse, product-based strategies were developed, implemented in experimental prototypes, and compared with linear alternatives: crushed concrete became building blocks, unreinforced concrete slabs were transformed into a point foundation, and a timber–concrete hybrid ceiling was constructed. The aim of this research project is to support the integration of concrete reuse into practice and to demonstrate that concrete.matters.