Fresh and hardened properties of 3D printable polymer-fibre-reinforced high-performance cementitious composite

The aim of this research was to develop a three-dimensional (3D) printable high-performance cementitious composite (CC) reinforced with polyvinyl alcohol (PVA) and polypropylene (PP) fibres. The characteristics of the fresh mortar were identified by conducting tests for rheological behaviour, flow factor and green strength. The mechanical properties of 3D printed specimens under different curing conditions were investigated in different printing directions and compared with those of cast specimens. The addition of a relatively small volume fraction of fibre (0.2%) led to a noticeable increase in yield stress, flow loss and green strength. For the hardened CC, the influence of a small amount of PVA or PP fibre was not significant in terms of the compressive and flexural strengths of the printed samples. The mechanical properties of cast and printed specimens in the hardened state was explained through the pore content, measured using X-ray micro-computed tomography.