CALCESTRUZZI INNOVATIVI ED ECOLOGICI ANCHE A SUPPORTO DELLA DIGITAL FABRICATION

The research activity presented in this thesis was aimed at researching new cement mixtures that can be used in order to be adopted in innovative construction pro-cesses through digital concrete, or 3D printing. In fact, it was possible to design mix-tures which satisfy the parameters required in order to be able to apply such mor-tars in robotic extrusion processes while maintaining good workability of the mortars. However, these choices were made while maintaining the goal of making mortars with very high mechanical characteristics, with a particular focus on the "eco-sustainability" of the mortar. For this reason, industrial waste materials, such as silica fume and biochar, have also been added to the mixture recipe. The experimental activity had a solid basis from the study of a mix design of a literature mortar that presented good performance, which was then adapted to local materials by introducing four different types of aggregate and different percentages of water-to-cement ratio and super-plasticizer on concrete. At a later stage, exploiting the results and knowledge obtained during the first experimental phase, a second test campaign was drawn up which instead exploited other types of more innovative and ecological materials, such as silica fume and biochar, studied both applied to mortars individually and in conjunction with each other in different percentages. Furthermore, in order to embrace the study of the applicability of these mortars for industrial purposes, we proceeded to the third operational phase of research aimed at verifying the printability conditions of the mortars, evaluating the variation in the strength of the mortars based on the type of curing to which it is subjected, if in the air then without the application of formworks, or if in wet. In fact, formwork has a very important effect both for the development of mechanical performance and for the durability of the manufactured articles, as will be described in more detail in the next chapter. Finally, the “carbon footprint” of the mortars was checked, carrying out a calculation of their ecological potential, assessed on the basis of the emission of equivalent carbon dioxide to produce one cubic meter of mortar.