Research Summary Report of C09

M. Eng. Sophie Viktoria  Albrecht                  Researcher, Sophie.albrecht@oth-regensburg.de

Prof. Charlotte Thiel                                          Project leader, charlotte.thiel@oth-regensburg.de

Ostbayerische Technische Hochschule Regensburg (OTH), Construction Materials

C09 aims to enhance the ecological sustainability of Additive Manufacturing in Construction (AMC) by quantifying and optimizing its environmental benefits through comprehensive Life Cycle Assessments (E-LCA) from cradle to cradle. This involves developing transparent Product Environmental Footprint Category Rules (PEFCR), identifying impactful reduction measures, and integrating circular design strategies to create durable, efficient, and reusable components. By incorporating these findings into Fabrication Information Modelling (FIM), C09 enables early-stage, sustainability-focused decision-making, fostering material-efficient, low-impact construction practices and reducing the environmental footprint of the building sector.

Summary

Additive Manufacturing in Construction (AMC) facilitates the production of complex, customizable, and multifunctional components that promote material-efficiency, durability, and circular construction practices.

Project C09 focuses on quantifying and optimizing these benefits through cradle-to-cradle Environmental Life Cycle Assessments (E-LCA). To ensure transparency and high-quality evaluation, Product Environmental Footprint Category Rules (PEFCR) are developed, and dominance analyses are conducted to pinpoint key environmental impact factors.

Collaboration with experimental A-projects provides critical insights into the most impactful and feasible measures for mitigating environmental impacts. At the component and structural levels, circular economy strategies guide the design of efficient, long-lasting, and reusable construction elements, further enhancing ecological sustainability.

The project investigates key questions regarding AMC’s environmental footprint, the role and effectiveness of circular design strategies, and the optimal manufacturing processes in terms of performance and sustainability. By improving materials and processes, C09 aims to significantly reduce the environmental impact of the construction industry while advancing sustainable and circular building practices.

The analysis of additively manufactured cementitious lost formwork in construction, shown in Fig. 1, highlights its potential to supersede conventional single-use wooden formwork, which significantly contributes to material waste and environmental impact. Lost formwork, designed to remain integrated into the structure, eliminates the need for removal after casting, thereby reducing labour and resource consumption.

Current state of research

Current research in construction emphasizes documenting the materials used during life cycle phases A1 to A3 – raw material supply (A1), transport (A2), and manufacturing (A3) – to provide a comprehensive understanding of their environmental impacts. This includes detailed records of material types, compositions, and sourcing practices, with a focus on integrating recycled and sustainable alternatives. Simultaneously, robotic 3D printing units are documented to track which materials they utilize during each process. This ensures transparency in the compatibility and efficiency of materials with robotic systems while enabling optimization of workflows and resource utilization. The current research has also established the functional units for the A-projects, providing a clear framework for analysis and comparison. Additionally, the research investigates the development of slab and wall elements that are optimized for structural integrity, ecological impact, and multifunctionality. These elements combine material efficiency, enhanced durability, and additional functionalities, adhering to circular economy principles to promote more sustainable construction practices. By integrating comprehensive material documentation with cutting-edge robotic fabrication processes, the project supports the creation of advanced, sustainable building components tailored for future-ready applications.

Current publications

[1] Thiel, Charlotte; Hechtl, C. Maximilian; Gehlen, Christoph; Kränkel, Thomas (2024): Sustainability Potential of Additive Manufactured Concrete Structures – Studies on the Life Cycle Assessment and Circularity of an Extruded Exterior Wall. In: Fourth RILEM International Conference on Concrete and Digital Fabrication.

[2] Albrecht, Sophie Viktoria; Hellerbrand, Stefan; Weininger, Florian; Thiel, Charlotte (2024): Possibilities for Reducing the Environmental Impact in the Construction Industry Using the Example of a 3D Printed Staircase. In: Proceedings of the 4th International Conference on Sustainable Development in Civil, Urban and Transportation Engineering.

[3] Albrecht, Sophie Viktoria; Hellerbrand, Stefan; Weininger, Florian; Thiel, Charlotte (2024): Strategies for Minimizing Environmental Impact in Construction: A Case Study of a cementitious 3D Printed lost formwork for a Staircase. In: Materials. (submitted)