Use of creep and recovery protocol to assess the printability of fibre-reinforced 3D printed white Portland cement composites

Abstract

ABSTRACT White Portland cement is an ideal choice for producing 3D printed coloured composites due to its inherent whiteness. However, the uncontrollable rheological properties limit the establishment of printed structures and thus affect the mechanical properties. In this study, the polyvinyl alcohol (PVA) and polypropylene (PP) fibres were utilised as reinforcement materials in 3D printed white Portland cement composites (WPCCs) to improve the printability and toughness by controlling creep properties, aiming to build better printed structures. Experimental results show that the addition of PVA and PP fibres effectively improve the creep properties of WPCCs, and printed structures can be well built by controlling creep properties. Specifically, the thixotropy of WPCCs with PVA and PP fibre is improved within specific content ranges of 0∼1% and 0.4∼0.8%, respectively. Compared with reference sample, the flexural strength increases by approximately 148.8% and 90.2% when the PVA and PP fibre contents reach 1.25% and 1%, respectively.