Effect of Toolpath Strategies on Anisotropy and Structural Performance of 3D Printed Concrete Gyroid Walls (2026-03)¶

The modern construction industry is increasingly seeking methods to improve efficiency through the creation of optimized structural geometries. 3D printed concrete (3DPC) promises the flexibility to create such forms but often struggles with complex shapes due to the impact of gravitational forces on layer overhangs. The gyroid, a triply periodic minimal surface known to efficiently distribute stress under compression, serves as a prime example of such limitations. Presently, research on concrete gyroids has been limited to smaller scales and often requires supporting material to maintain shape. This study demonstrates the ability for 3DPC gyroid walls to be fabricated without support and determines the impact of two different toolpaths on their overall performance. In a closed toolpath strategy, the printed layer must perform a complete circuit of the geometry with a constant interlayer time, resulting in the need for additional material to complete the loop of the wall. Conversely, an open toolpath may instead switch printing directions between ends of the geometry with every layer, using less material at the cost of a variable interlayer time. The presented findings indicate that the closed toolpath gyroid outperforms the open toolpath gyroid, with approximately a 45% difference in load carrying capacity and a 30% difference in capacity-to-mass ratio. Visual analysis and anisotropic material tests revealed a potential weakness in the open toolpath design. With further optimization, both designs could see improved performance and use in relevant structural applications, advancing the use of complex printed geometries in concrete construction.