Re-connecting brick waste
Exploring additive manufacturing for circular reuse
Germany generates nearly 200 million tonnes of construction and demolition waste (CDW) each year, with brick and concrete representing over a quarter of this total. While reported recovery rates are high, reclaimed bricks are often downcycled into aggregates, losing both their structural potential and cultural value.1 This project develops digitally fabricated connector systems that allow damaged or irregular bricks to be reused. By combining mapping of waste brick flows, additive manufacturing, and collaborative reflection, the research explores how imperfect materials can re-enter high-value construction processes. Hamburg serves as a case study for prototyping and stakeholder engagement, aiming to create workflows that are adaptable across urban contexts.
- circular built environment
- construction and demolition waste
- additive manufacturing
- brick reuse
- co-reflection
Context
Construction and demolition waste has become a defining challenge for sustainable cities. Although CDW is often described as a technical problem of logistics or recycling, it also represents how societies value their materials, and future resilience of those materials. Bricks, as one of the oldest and most widespread building elements, illustrate this tension; while durable, they often lose their reuse potential because of mortar residues and breakage. Yet these very characteristics open up design opportunities for alternative reuse strategies that embrace irregularity instead of eliminating it. Current approaches often prioritize recycling or downcycling, which leads to significant energy and resource losses.2 In recent years, digital fabrication has shown how different materialities can be reintegrated into architectural workflows. Emerging examples demonstrate how 3D printing and robotic processes can integrate local material realities into design. However, these projects rarely address the reuse of discarded materials directly. This research responds to that gap by integrating additive manufacturing into reclaimed brick cycles, connecting design innovation with material flows in Hamburg.
Aims
The research pursues six core objectives:
- Develop and test proof-of-concept 3D-printed dry-joint connectors for reclaimed bricks.
- Generate empirical knowledge on reclaimed brick tolerances and behaviour.
- Build a design-led workflow that connects digital fabrication to CDW reuse.
- Facilitate stakeholder reflection through a workshop.
- Contribute to circular construction in both practice and pedagogy.
- Advocate for reuse strategies as replicable methods.
Research design
The project follows a design-led, iterative methodology organized into four work packages:
- Mapping CDW brick flows and relevant actors of the processes in Hamburg through site visits, interviews, and GIS analysis.
- Digital capture and modelling of reclaimed bricks via 3D scanning and parametric design.
- Prototyping dry-joint connectors using additive manufacturing, testing disassembly.
- Conducting collective reflection session with stakeholders to evaluate usability, scalability, and systemic barriers.
The methodology treats prototypes not as finished products, but as test situations where feasibility, values, and barriers are negotiated.3 Inspired by the precedent works demonstrating how 3D scanning and parametric workflows can adapt digital tools to damaged materials,4 and by extending this logic to brick waste, the research frames reuse as a process shaped by material and social negotiation.5 Experiments within the scope of research bridge technical innovation and collaborative practice, and connect these to material realities of the urban context.
Supervisors:
