Combining recycling of paper wastes (WPs) with extrusion‐based additive manufacturing represents a sustainable route to cellular cellulose composites tailored for lightweight construction. Particularly, shear mixing of shredded WPs with an aqueous solution of a polymer binder like polyvinyl alcohol (PVA) yields aqueous pastes suitable for 3D printing. As a shear thinning additive, both WP and microfibrillated cellulose account for enhanced shear thinning and dimensional stability. Opposite to the formation of dense WP/PVA composites by melt extrusion, 3D printing of aqueous pastes produces cellular cellulose/PVA composites exhibiting hierarchical pore architectures. In spite of low densities around 0.8 g cm−3, high Young’s…
Freedom of design, customisation, automation, waste minimisation, reduced labour and building complex structures with cheaper materials are the main initiatives for developing 3D printed structures. The fresh properties of concrete are the most important aspects of a successful 3D printing. Concrete requires high workability for extrusion, optimum open time and high early strength in order to support the subsequent layers for 3D printing. Therefore, a mixture design that can satisfy these requirements is needed. Geopolymer concrete is a sustainable solution to traditional Portland cement-based concrete that uses waste materials. In addition, the controlled alkali-activation of geopolymer precursors in order to…