A Novel Approach to Additive Manufacturing (2026-03)¶

Driven by innovative technologies and materials, the construction industry is undergoing continuous change. More specifically, 3D printing of concrete will revolutionize the industry because it provides the option of constructing complex buildings and structures directly from printable concrete. However, this process is associated with high demands on the rheological characteristics of concrete. It must remain flowable during conveying and printing and become dimensionally stable (green strength) quickly after discharge without damaging previously deposited layers. Some commercially available material solutions rely on adding a setting accelerator for this purpose, but this type of admixture is difficult to batch and can cause blockage if the printing process is interrupted unintentionally. Our approach (Fig. 2) aims to overcome these problems. To achieve this goal, IAB Weimar developed an innovative vibratory concrete print head in our preliminary research that uses concrete recipes with a maximum particle size of 8 mm and sustainable binders. Targeted use of mechanical vibration on the print head makes it possible to liquefy the fresh concrete during the 3D printing process, which triggers its discharge with the aid of gravitational force. This method relies on utilizing the thixotropic properties of the material, which allow for precise modulation of its rheological parameters during the discharge process.