3D printing affordable, sustainable and resilient housing in Alaska

HUD issued funding to the city of Nome, which then turned to the Xtreme Habitats Institute (XHI), an Alaska-based non-profit corporation with a mission to research, test and demonstrate new technologies that have the potential to improve living and working conditions in rural Alaska. XHI will work with AddConLab faculty, the Cold Climate Housing Research Center (CCHRC,) the National Renewable Energy Laboratory (NREL) and X-Hab 3D, a State College-based robotics and materials company co-founded by Duarte that has developed a mobile, expeditionary 3D concrete printing system that will be used to print the demonstration housing structures for the project. Three doctoral students — one in architecture and two in engineering — will also work on the structural aspects and material development of the project.

Sven Bilén, professor of engineering design, electrical engineering and aerospace engineering, and the lead of systems engineering at X-Hab 3D, and Shadi Nazarian, H. Ralph Hawkins, FAIA, Chair in Architecture at the University of Texas at Arlington and the lead for architectural design and advanced materials at X-Hab 3D, will also work on the project. They will be joined by Nate Watson, XHab 3D’s vice president of engineering and product and a Penn State College of Engineering alumnus with a master’s degree in additive manufacturing. Bilén will travel to Alaska to assess the performance of the mobile 3D printer and to assist with on-site logistics.

Ali Memari, professor and Bernard and Henrietta Hankin Chair in Residential Building Construction, will lead the structural team on the project, which will 3D print concrete wall specimens and, after adding steel reinforcing bars in selected cavities embedded in cast concrete, test the walls for flexural strength, which is resistance to bending under horizontal wind pressure.

The team will add rebars in the cells of the printed concrete and fill the cell with cast concrete to strengthen the wall in resisting the horizontal wind pressure. To show if the wall has enough capacity to resist the wind load, they will use the material and section properties of the concrete wall and equations that can predict the resistance of the wall to bending. 

“The results of such tests can then be used for structural load resistance calculations,” Memari said. These calculations will predict the wall’s resistance to bending under pressure.