Mechanical and rheological properties of 3D printable cement composites

Abstract

Additive manufacturing is a recent revolution in the construction field since cementitious materials became printable. This extrusion technique has enabled the construction of very complex geometry with a reduction in costs, time and labour interventions. This study aims to evaluate the possibility of reinforcing 3D printable cementitious composites with the use of nano and micro materials, particularly nano silica, micro silica and microfibrillated cellulose (MFC) which are known for their ability to enhance the fresh and hardened properties of cement-based composites. Rheology property test, flowability and mechanical properties are the types of tests performed to evaluate the fresh and hardened properties of mortar modified with the rested additives. The results show the addition of MFC of 0.4% (of total solid matter) can significantly enhance the mechanical property. In addition, the presence of MFC (at 0.4% of total solid matter) can reduce the pressure required to extrude the mortar, enabling a steady state extrusion. It was also found that 1% nano silica addition significantly improves the mechanical properties and minimizes segregation in the failure surface.