@article{AlbrechtHellerbrandWeiningeretal., author = {Albrecht, Sophie Viktoria and Hellerbrand, Stefan and Weininger, Florian and Thiel, Charlotte}, title = {Strategies for Minimizing Environmental Impact in Construction: A Case Study of a Cementitious 3D Printed Lost Formwork for a Staircase}, series = {materials}, volume = {18}, journal = {materials}, publisher = {MDPI}, doi = {10.3390/ma18040825}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-79236}, pages = {18}, abstract = {The construction industry faces significant challenges, including environmental sustainability, rising material costs, and a shortage of skilled labor. Digital fabrication technologies offer innovative solutions to address these issues by reducing raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an Environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, this study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and abiotic depletion potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low-clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities}, language = {en} } @inproceedings{AlbrechtThielHellerbrandetal., author = {Albrecht, Sophie Viktoria and Thiel, Charlotte and Hellerbrand, Stefan and Weininger, Florian}, title = {Possibilities for Reducing the Environmental Impact in the Construction Industry Using the Example of a 3D Printed Staircase}, series = {Proceedings of the 4th International Conference on Sustainable Development in Civil, Urban and Transportation Engineering (CUTE 2024), 14-17 October, Wrocław, Poland}, booktitle = {Proceedings of the 4th International Conference on Sustainable Development in Civil, Urban and Transportation Engineering (CUTE 2024), 14-17 October, Wrocław, Poland}, publisher = {Springer Nature}, isbn = {978-981-97-9400-3}, doi = {10.1007/978-981-97-9400-3_6}, pages = {55 -- 64}, abstract = {The construction industry faces numerous challenges, including environmental sustainability, high material costs, and a shortage of skilled labor. Modern technologies enabling digital fabrication present opportunities to reduce raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, the study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and Abiotic Depletion Potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities.}, language = {en} } @inproceedings{PfahlerThielNeidhart, author = {Pfahler, Katharina and Thiel, Charlotte and Neidhart, Thomas}, title = {Einfluss der Probengeometrie auf die Mechanischen Eigenschaften von Stampflehm - Eine Literaturrecherche}, series = {ce/papers - Proceedings in Civil Engineering}, volume = {8}, booktitle = {ce/papers - Proceedings in Civil Engineering}, number = {1}, publisher = {Ernst \& Sohn, a Wiley Brand}, issn = {2509-7075}, doi = {10.1002/cepa.3291}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-80291}, pages = {57 -- 68}, abstract = {Der Klimawandel lenkt den Fokus im Bauwesen zunehmend auf die Reduktion von Treibhausgasen und die F{\"o}rderung nachhaltiger Materialien. Baustoffe wie Lehm gewinnen dank ihrer {\"o}kologischen und bauphysikalischen Vorteile an Bedeutung. Eine zentrale Herausforderung stellt die Definition standardisierter Pr{\"u}fmethoden f{\"u}r Stampflehm dar. Dieser Beitrag analysiert Forschungsergebnisse zur Geometrie von Stampflehmprobek{\"o}rpern mittels Literaturrecherche und vergleicht experimentelle Untersuchungen sowie relevante Normen und Testmethoden. Die Auswertung zeigt, dass {\"a}ußere Einfl{\"u}sse wie Mischungszusammensetzung, Verdichtungsenergie, Gesteinsk{\"o}rnung und Tonminerale eine zentrale Rolle spielen. Eine Vereinheitlichung von Probengeometrie, Lagerung und Pr{\"u}fverfahren ist essenziell, um reproduzierbare Ergebnisse zu erzielen und die mechanischen Kennwerte von Stampflehm vergleichbar zu machen. Ziel ist es, einheitliche Standards zu entwickeln, um die Stampflehmbauweise in der Praxis zu f{\"o}rdern.}, subject = {Lehmbau}, language = {de} } @article{SchmidThiel, author = {Schmid, Michael T. and Thiel, Charlotte}, title = {Is it worth it? Potential for reducing the environmental impact of bitumen roofing membrane production}, series = {Recycling}, volume = {10}, journal = {Recycling}, number = {6}, publisher = {MDPI}, doi = {10.3390/recycling10060208}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-86873}, pages = {24}, abstract = {Between 51\% and 72\% of a bituminous roofing membrane used for structural water-proofing consists of organic material, predominantly bitumen - a derivative of crude oil refining - highlighting the strong dependence of this product on fossil resources. Considering that several tonnes of these membranes must be replaced every 30 to 50 years, substantial potential exists for emission reduction through the establishment of circular material systems. This study investigates this potential by analysing 26 Environmental Product Declarations (EPDs) and life cycle datasets from across Europe covering the period from 2007 to 2023. To ensure comparability, all data were normalised to a declared unit of 1 kg of roofing membrane. The reinforcement layers were categorised into glass and polyester \& glass composites, and their differences were examined using Welch's t-tests. Correlative analyses and linear as well as multiple regression models were then applied to explore relationships between environmental indicators and the shares of organic and mineral mass fractions. The findings reveal that renewable energy sources, although currently representing only a small share of total production energy, provide a major lever for reducing nearly all environmental impact categories. The type of reinforcement layer was also found to influence the demand for fossil resources, both materially and energetically. For most environmental indicators, only multiple regression models can explain at least 30\% of the variance based on the proportions of organic and mineral inputs. Overall, the study underscores the crucial importance of high-quality, transparently documented product data for accurately assessing the sustainability of building products. It further demonstrates that substituting fossil energy carriers with renewable sources and optimising material efficiency can substantially reduce environmental burdens, provided that methodological consistency and clarity of indicator definitions are maintained.}, language = {en} } @techreport{SigwarthBuechnerWistubaetal., author = {Sigwarth, Tess and B{\"u}chner, Johannes and Wistuba, Michael and Geiger, Lydia and Knittlmayer, Christian and R{\"a}decke, Christoph and Seelig, Karsten and Schmid, Michael and Thiel, Charlotte and Tumakov, Konstantin and Ditscherlein, Lisa and Peuker, Urs Alexander}, title = {Forschungsbericht REBIBA - Recycling von Bitumenbahnen f{\"u}r Bauwerksabdichtungen}, address = {Braunschweig}, doi = {10.24355/dbbs.084-202510301114-0}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:084-2025103011147}, pages = {74}, abstract = {In Europa werden ca. 62 \% aller neuen Flachd{\"a}cher mit Bitumenbahnen abgedichtet (Das Dachdecker-Handwerk, 2023). Bitumenbahnen bestehen typischerweise aus einem Tr{\"a}germaterial - einem Glas-moder Kunststoffvlies. Dieses ist beidseitig mit Bitumen(-massen) beschichtet. Diese Bitumenmassenbestehen zu einem großen Anteil aus erd{\"o}lbasiertem Bitumen, dessen Herstellung viel Energieverbraucht und somit einen hohen Emissionsausstoß aufweist. Am Ende der Nutzungsdauer vonBitumenbahnen werden diese aufgrund ihres Heizwertes thermisch verwertet.Mit diesem Forschungsprojekt wurden die wissenschaftlichen und technischen Hindernisse f{\"u}r diestoffliche Verwertung und das kontinuierliche Recycling von bitumin{\"o}sem Abdichtungs- undDachbahnen-Abfall in Deutschland eruiert. Dazu wurden alle Verarbeitungsschritte zur Gewinnung undAufbereitung von wiedergewonnenen Bitumenbahnen aus Bauabf{\"a}llen als wertvolle Ressource f{\"u}rAnwendungen im Hochbau in Form neuer Bitumenbahnen betrachtet. Hierzu wurden zun{\"a}chstunterschiedliche Aufbereitungstechniken erprobt, um die Bitumenmasse von den Tr{\"a}gereinlagenabzutrennen. Zur Charakterisierung der Bitumenmassen und deren Alterungsverhalten wurdenrheologische Pr{\"u}fverfahren im Dynamischen Scherrheometer durchgef{\"u}hrt. Diese erlauben dieBeurteilung der viskoelastischen Eigenschaften und des Gebrauchsverhaltens bei W{\"a}rme und beiK{\"a}lte. Anhand der rheologischen Pr{\"u}fungen wurde das Alterungsverhalten von Bitumenmassenumfassend untersucht, um daraus die Grundlage f{\"u}r die Rezepturentwicklung von rezykliertenBitumenmassen zu erstellen.Aus den zerkleinerten Rezyklaten konnten Prototypen von Bitumenbahnen mit Recycling-Anteilen vonbis zu 37 \% hergestellt werden. F{\"u}r die großtechnische Umsetzung des Recyclingverfahrens ist dieAbtrennung der Tr{\"a}gereinlagen und m{\"o}glichen mineralischen Abstreuungen anzustreben. Die begleitende {\"O}kobilanzierung zeigte ein Einsparpotenzial bei den Treibhausemissionen (GWP) vonbis zu 33,0 \%. Unter Einbindung erneuerbarer Energien ist eine Reduktion von bis zu 43,1 \% denkbar. Im Bereich der nicht erneuerbaren Prim{\"a}renergie (PENRT), die sich bei Bitumendachbahnen haupts{\"a}chlich aus materiellen und energetischen fossilen Stoffen zusammensetzt, kann etwa die H{\"a}lfte davon eingespart werden. Das ist den 80 \% des Bitumenmaterials zuzuschreiben, die maximal prozesstechnisch substituiert werden k{\"o}nnen, was schließlich deutlich h{\"o}her ausf{\"a}llt, als die theoretischen Einsparpotentiale im Treibhauspotential.}, language = {de} } @techreport{AlbrechtThiel, author = {Albrecht, Sophie and Thiel, Charlotte}, title = {Environmental life cycle assessment - determination of ecological sustainability potentials by AMC}, series = {Research Summary Report of C09 2025}, journal = {Research Summary Report of C09 2025}, publisher = {AMC}, abstract = {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. C09 enables early-stage, sustainability-focused decision-making, fostering material-efficient, low-impact construction practices and reducing the environmental footprint of the building sector.}, language = {en} } @inproceedings{AlbrechtThielKaramara, author = {Albrecht, Sophie Viktoria and Thiel, Charlotte and Karamara, Merve}, title = {Decoding concrete's environmental performance: A detailed analysis of global EPDs across the entire life cycle}, series = {MATEC Web of Conferences}, volume = {409}, booktitle = {MATEC Web of Conferences}, publisher = {EDP Sciences}, address = {Les Ulis}, doi = {10.1051/matecconf/202540913001}, pages = {10}, abstract = {Environmental Product Declarations (EPDs) for concrete are essential tools to quantify the environmental impact of this versatile building material throughout its life cycle, supporting sustainable choices in construction. Concrete is made up of raw materials like cement, water, aggregates, additives, and admixtures, which can be mixed in diverse ways. This variability often necessitates site-specific EPDs, as emissions and environmental impacts depend greatly on cement type, transport routes, and specific production processes. This study analyses various data sources, focusing on EPDs according to ISO 14025 and EN 15804. The life cycle phases A1-A3, B1-B7, C1-C4 and D are considered and compared. The results demonstrate that factors such as scenario assumptions, methodological choices, and allocation procedures significantly influence concrete's environmental impact. Transparent EPDs improve assessment reliability, while allocation methods, especially in phases D and end-of-life, significantly influence reported benefits, underscoring the importance of careful allocation for accurate impact evaluations. Improved standardisation, transparency, and alignment with EN 16757 would enhance EPD comparability and reliability. Overall, the study identifies key parameters such as recycling potential, production stage and allocation methods as substantial factors in the environmental performance of concrete.}, language = {en} }