Timber construction has resurged in recent years, especially in multi-story and large-scale projects, driven by its sustainability and carbon storage capacity. Yet, modern timber faces two major challenges: low material efficiency in products like CLT and glulam, where sawing and planning waste much of the raw material, and dependence on high-quality roundwood for production. This FFG-funded project “Unistrand” develops a strand-based wood material for mass timber applications in multi-story buildings. Made from unidirectionally oriented softwood and hardwood strands, it achieves high material yield (>75%) and superior mechanical properties. By utilizing diverse wood species, the project addresses industry challenges and adapts to changing forest resources under climate change, promoting sustainable timber use in future construction.

The Unistrand project is a collaborative effort between the Institute of Green Civil Engineering and the Institute of Wood Technology and Renewable Materials at BOKU University, encompassing four dedicated work packages. Within this framework, the Institute of Green Civil Engineering is responsible for two work packages. Work Package 4 focuses on the experimental testing of multi-layer Unistrand panels to evaluate their mechanical behavior under bending, shear, compression, and tension. The resulting data provides the foundation for material modeling and structural design, ensuring their safe application in multi-story buildings. Work Package 5 extends this research towards structural optimization and parameterization of the panels, aiming to maintain mechanical performance while reducing weight. This approach enhances both efficiency and the suitability of Unistrand panels for modern multi-story construction.

Find more Information here: www.holzcluster-steiermark.at/projekte/unistrand/
 

Contacts:

Univ.Prof. Dipl.-Ing.Dr.techn. B.Sc. Benjamin Kromoser
Univ.Prof. Dipl.-Ing.Dr.techn. B.Sc. Benjamin Kromoser
MSc Ahmadreza Ghazanfari
MSc Ahmadreza Ghazanfari
MSc Johannes Karl Belz
MSc Johannes Karl Belz

Archive:

Large tension tests performed for the UNISTRAND project

EMI 2024 in Wien

UniStrand Project – Second-Year Consortium Meeting

IASS 2024 in Zürich

Partner:

Publications:

Ghazanfari A, Kromoser B. Numerical modeling and sensitivity analysis of unidirectional strand board (USB) for structural applications. In: Füssl J, Lukacevic M , editors. The CompWood 2025 - Program & Book of Abstracts [Internet]. DOI: TU Wien / CompWood 2025; 2025. Available from: tucloud.tuwien.ac.at/index.php/s/kiAM7aqXXeZZQJw
 

Ghazanfari A, Kromoser B. Multi-Layer Strand-Based Wood Material in Construction: Mechanical Properties and Test Methods. In: Rischmiller, K , editor. World Conference on Timber Engineering 2025. Advancing Timber for the Future Built Environment [Internet]. Curran Associates Inc. Proceeding; 2025. DOI:10.52202/080513-0620
 

Ghazanfari A, Malzl L, Pramreiter M, Konnerth J, Kromoser B. A systematic review of strand-based engineered wood products for construction: standard test methods and mechanical properties. Wood Material Science and Engineering [Internet]. 2025;. DOI:10.1080/17480272.2025.2465562
 

Ghazanfari A, Malzl L, Pramreiter M, Myna R, Konnerth J, Kromoser B. Shear performance of single-layer unidirectional strand board (USB): modified testing methods. Wood Material Science and Engineering [Internet]. 2025;.DOI:/full/10.1080/17480272.2025.2478600
 

Ghazanfari A, Kromoser B. Characterizing a novel strand-based engineered wood product for the use in construction. In: Hellmich C, Pichler B, Schneider S , editors. EMI 2024 IC - Program & Book of Abstracts [Internet]. Technische Universität Wien (TU Wien); 2024. Available from: www.emi2024ic.com/wp-content/uploads/2024/08/emi2024ic-program-bookofabstracts.pdf
 

Malzl L, Fasalek A, Ghazanfari A, Belz J, Kromoser B, Konnerth J, et al. Strand-based Mass Timber: Bending performance of cross-wise adhered unidirectional pine LSL. In: Morrell, J , editor. Proceedings of the 67th SWST International Convention [Internet]. Society of Wood Science and Technology; 2024. Available from: www.swst.org/wp/wp-content/uploads/2024/08/SWST-2024-Final-Proceedings-Editor-copy.pdf
 

SWST International Convention [Internet]. Society of Wood Science and Technology; 2024. Available from: https://www.swst.org/wp/wp-content/uploads/2024/08/SWST-2024-Final-Proceedings-Editor-copy.pdf

Belz J., Kromoser B., An Accessible Framework for Optimizing the Structural Performance of Wood-based Building Components, Proceedings of the IASS 2024 Symposium, 2024. Available from: https://www.researchgate.net/publication/384286699_An_Accessible_Framework_for_Optimizing_the_Structural_Performance_of_Wood-based_Building_Components

Belz J., Kromoser B. Structural optimization of wooden building components: a systematic review of established practices, Wood Material Science and Engineering [Internet]. 2025;. DOI: /full/10.1080/17480272.2025.2525328
 

Belz J., Kromoser B. Advancement on the Sturctural Timber Optimizer (STO) In: Rischmiller, K , editor. World Conference on Timber Engineering 2025. Advancing Timber for the Future Built Environment [Internet]. Curran Associates Inc. Proceeding; 2025. DOI: 10.52202/080513-0257
 

Belz J., Kromoser B. Influence of Segmented Discrete Modeling and Interaction Types on Simulating Multilayered OSB Wall Elements In: Füssl J, Lukacevic M , editors. The CompWood 2025 - Program & Book of Abstracts [Internet]. TU Wien / CompWood 2025; 2025. Available from: tucloud.tuwien.ac.at/index.php/s/kiAM7aqXXeZZQJw