An experimental study on earth-based mixes with waste materials for 3D printed blocks

This study aims to experimentally realize and test earth-based mixes to be used as construction materials for 3D printing. The analyzed mixes are realized with waste materials, to minimize the environmental impacts. Among the candidate waste, rice husk (RH), marble dust (MD) and municipal solid waste incinerator bottom ash (MSW-IBA) are selected. To ensure a successful 3D printing process for constructing one- or two-story buildings, we combined the materials mentioned above with two types of binders to cast earth-mortar mixtures. The physical, chemical and mineralogic characteristics of the raw materials are analyzed, whereas fluidity and mechanical properties of the mixes are analyzed. Specifically, the results of the tests on the fresh mortars and on the hardened blocks, cured for the 28 days, were used to evaluate if the realized mixes meet the basic criteria for guaranteeing an effective 3D printing process.