Buzzi Unicem USA and Lehigh University have established a strategic partnership spanning research, recruitment, outreach and cultural activities. 
The flagship project of this industry-academia collaboration focuses on the development of a new methodology for 3D printing concrete components and structures. 
The methodology developed by Lehigh and Buzzi Unicem consists in precisely jetting micro-droplets of a water-based liquid on extremely thin layers of concrete and fine aggregates. The printer automatically spreads layer after layer of the dry mix, and the automated print-head selectively activates the cement hydration only in the locations that are needed for that layer, by jetting droplets only in those regions. The inert cement and aggregates serve as support for the following layers, allowing the creation of openings, cavities, and overhangs. At the end of the printing process, the dry mix that did not react can be easily collected and reused. This manufacturing process is completely automated and free from the constraints of traditional formwork, which also enables the manufacturing of geometries that could not be formed with traditional casting. 

After a broad range of tests, Buzzi Unicem CSA cement emerged as the best option for the binder, especially due to its fast setting time and its ability to rapidly absorb water, which is important to prevent “bleeding” of water to locations where hydration should not occur and preserve geometric accuracy. The collaboration between Buzzi Unicem and Lehigh was also brought to the attention of the State of Pennsylvania, which decided to co-fund the effort. In the future, the project will aim at increasing the size of the produced objects, through the use of larger printers and modular printing of components assembled with post-tensioning cables. 
While the methodology is not yet ready to be deployed in practice, it has the potential to revolutionize the precast industry, and the entire construction sector.