The selection and design of earthen materials for 3D printing

Significant efforts are being made to reform the construction industry using 3D printing. Among an extensive variety of printing materials, eco-friendly earth materials have recently received increased attention. Nonetheless, corresponding research is limited, particularly in assessing the availability of earthen mixture and printing performance. This study presents a methodical and effective procedure for selecting earthen formulations for 3D printing. Four different soils were identified based on their characteristics, including granularity, clay behavior, and linear shrinkage, in order to select suitable construction materials. In addition, the rheological behavior (yield stress) of the earthen mixture was investigated so that printing formulations could be selected effectively. Finally, the printing performance was evaluated for establishing recommendations for selecting appropriate mixtures, and an analytical model of mass transfer based on the drying process for predicting the occurrence of plastic collapse was also proposed.