LOW TECH WASTE 3D PRINTING

Binder jet 3D printing of geopolymers is a newly developed manufacturing technique that combines a material with a low carbon footprint with a material-saving processing. In this work, the embodied energy of the printed building parts is further decreased by replacing the virgin silica sand with waste materials from local stone quarries. The use of the quarry waste in 3D printing could help to keep the business of small quarries running, since they face severe problems with the disposal of the waste. Test bars were printed with different grain sizes and tested on flexion and compressive strength, density and accuracy. The results show that the material is strong enough to be applied in structures loaded on compression only. 3D printing of quarry aggregates could help to valorise the locally available material and enhance the use in classical techniques as well, in order to reduce the amount of deposited material.