Name: Karoline Konstanse Ahlfors Mikalsen

Title of the project: 3D printing of concrete protective structures

Project description

Due to its high strength and durability, concrete remains the primary material used in fortification and infrastructure construction. However, its production accounts for approximately 8% of global CO₂ emissions, with cement manufacturing as the main contributor. To achieve global sustainability goals set by the United Nations, emissions from concrete production must be reduced. Developing sustainable concrete is therefore essential, and this can be achieved through innovative approaches to structural design and construction methods that optimize material usage.

3D printing of concrete has recently emerged as a promising technology, enabling optimized geometries and cross-sections that can lower material consumption. This technology also offers new construction methods that can reduce manual labor. However, its performance under extreme loading conditions remains largely unexplored, and its implementation in Norway is still limited. Moreover, while 3D printing can reduce total material use, the high cement content of printable concretes offsets much of the environmental advantage. Additional challenges include reinforcement integration and insufficient frost durability, both of which are critical to ensuring the long-term durability and performance of the structures.

To investigate the use of 3D-printed concrete as protective structures the following tasks will be undertaken:

1. Conduct state of the art research on experimental and numerical methods related to 3D printing of concrete.
2. Identify and evaluate key limitations, including issues related to reinforcement integration, high cement content, and frost durability.
3. Perform geometric optimization and preliminary numerical simulations.
4. Design and execute experimental tests on 3D-printed concrete structures exposed to extreme loading conditions.
5. Develop and calibrate numerical models to simulate and validate the experimental results.

The project is in collaboration with Forsvarsbygg, with additional contributions from Statsbygg, Veidekke, Heidenberg materials and Mechatronic Innovation Lab, in full-scale construction using 3D printing.

Date of start of PhD: October 2025