Green cement based material optimization for additive manufacturing in construction

Abstract

The rapid growth of 3D printing technology has led to the development of large-scale 3D printers that can print concrete. The process of 3D printing in concrete does not use formwork and thus gives increased flexibility to designers, saves the cost of labour and materials and reduces waste. These printers have been used to construct structural elements and full-scale buildings which have been the focus of a new age of 3D printers in the construction industry. The materials are an important part of the printing process, aiming to obtain a particular mix satisfying all the requirements of cementitious material. There is interest to broaden the focus on waste from construction industries and involving these wastes in 3D printing for sustainable construction, blending technology with the construction process. In this work, stone sludge was used as raw material in the mortar, having the objective to do 3D printing in a cost-effective and affordable way. The mortar was printed using a robotic arm with an extrusion printing process. Six mortars with different proportions of stone sludge and admixtures were tested in a systematic way to determine the printable properties of mortar. The bending and compressive strength of printed or casted samples were measured and compared.