The rise of 3D printing in the construction field continues to transform our approach to materials and implementation techniques. Among these advances, the incorporation of bentonite, metakaolin, microsilica and calcium carbonate into Portland cement-based 3D printing inks deserves special attention. These adjuvants, thanks to their specific properties, significantly influence the rheological performance of the mixtures. By optimizing fluidity, viscosity and behavior at the time of deposition, they not only improve the quality of the works produced, but also meet growing requirements in terms of durability and functionality. Thus, understanding the impact of these materials on 3D printing inks is essential to pushing the limits of this revolutionary technology even further.
Effect of bentonite on printing properties
The incorporation of the bentonite in Portland cement-based mixtures showed a significant impact on rheological properties. By adding between 1% and 5% bentonite, the results revealed an increase in viscosity and of static performance stress, thus promoting additive construction.
Influence of metakaolin and microsilica
The additions of metakaolin and of microsilica also improve the properties of the ink. At concentrations of 5% and 10%, these materials favorably modify the fluidity and the buildability mixtures, making the printing process more efficient.
Role of calcium carbonate
Regarding the calcium carbonate, its incorporation does not generate significant changes in the flow behavior. However, it plays an important role in acting as fluidifier, which negatively impacts the stability of printed patterns.
Assessment of mixture properties
To fully understand the contribution of these materials, it is essential to evaluate the properties of the mixtures in the fresh state, such as:
- Rheology : evaluation of flow and deformation behavior under stress.
- Viscosity : measurement of resistance to ink flow.
- Thixotropy : ability of mixtures to regain their structure after deformation.
- Buildability : ability of inks to maintain their shape during the printing process.
Materials and results obtained
Test results suggest that bentonite-enriched blends can provide significant improvement printing properties, while guaranteeing excellent structural recovery (thixotropy).
List of effects of additions on properties
| Material | Effect |
| Bentonite | Increases viscosity and static yield stress |
| Metakaolin | Improves the fluidity and strength of mixtures |
| Microsilica | Strengthens the buildability of print mixes |
| Calcium carbonate | Does not significantly affect flow behavior |
