Researchers atRWTH Aachen Universityare investigating whether steel scrap can be transformed into certified, load-bearing construction components using 3D printing. The BMWE-funded AddMamBa project focuses on producing optimized facade brackets from recycled steel powder via laser powder bed fusion (PBF-LB/M), aiming to reduce material consumption and improve circularity in the construction sector.
The research is led by the university’sChair Digital Additive Production(DAP) in collaboration withPaul Kamrath Ingenieurrückbau GmbH,RSB Rudolstädter Systembau GmbH, andLaser Melting Innovations GmbH. The project is funded by theGerman Federal Ministry for Economic Affairs and Energyunder the Lightweight Technology Transfer Program and managed byProject Management Jülich.
From steel scrap to PBF-LB/M-qualified powder
AddMamBa examines whether recycled structural steel can meet the quality requirements for additive manufacturing of load-bearing facade connections.
Steel scrap is first sorted according to age, grade, and condition before being chemically analyzed. The material is then converted into metal powder using gas atomization (VIGA). Following atomization, the powder is sieved to a particle size range of 15–45 micrometers, suitable for stable layer deposition in the PBF-LB/M process.
Approximately 60% usable powder was recovered during the trials, yielding 30 kg of powder from 50 kg of processed scrap.The recovery rate, combined with chemical sorting and atomization control, indicates that recycled structural steel can be processed into powder with characteristics suitable for structural additive applications.
Topology optimization and thermal performance
The project focuses on facade brackets for ventilated facade systems and structural connectors for load-bearing uses. Topology optimization places material along the load paths, reducing unnecessary mass while keeping mechanical performance.
In addition to structural performance, the optimized shapes are designed to reduce thermal bridging. The brackets can be adapted to the building geometry and substructure setup without dedicated tooling, allowing customized production without extra mold costs.
A digital planning tool developed within the project assists users in selecting appropriate bracket solutions. After entering facade and structural data, the system proposes suitable configurations while considering relevant standards, including DIN EN 1991-1-4/NA.
Source: 3D Printing Industry
