3D printing is a high productivity and precision technique with a low generation of residues. The 3D printing of cementitious materials as a construction method is a reality in some countries; however, there are challenges to consolidate it in the building industry. Compared to traditional applications, the cementitious materials used in 3D printing have new requirements from fresh to hardened states. In this context, optimizing the rheological and mechanical properties of the cementitious-based materials within this specific application is fundamental. 
The main challenges can be listed in 2 topics: 1- the adjustment of adequate workability that allows the extrusion but still resists the weight of the overlaid layers of material that is still fresh, and 2- grip between the layers successively deposited.
To avoid mechanical/grip problems on concrete, macrofibers are usually used (metallic or polymeric ones), but they are unviable for 3D printing due to execution limitations. Thus, this project will evaluate the incorporation of micro/nanofibers of different types (carbon, SiC, etc.) for the improvement of the mechanical properties of printed elements, also evaluating the impact on rheological properties and suitability for printing. Additionally, alternative binders (geopolymers) will be evaluated, contributing to the development of sustainable building materials. The use of micro/nanofibers in cementitious bases has been widely investigated in the last few years, resulting in significant increments in mechanical performance. However, practically, the application of these micro/nano reinforcements wasn’t explored for 3D printing applications. Therefore, it will be evaluated how the incorporation of micro/nanofibers affects several properties (specially printability) of cementitious materials and alternative binders.

Objectives: to produce Portland cement-based materials with fresh state properties compatible with 3D printing application; to produce alternative binders (e.g., LC3 cement and geopolymers) based materials with fresh state properties compatible with 3D printing application; to incorporate different nanomaterials in fresh state cementitious materials; to evaluate the effects of nanomaterials on the mechanical properties of cementitious materials.