Effect of process parameters on forming quality and flexural strength of continuous fiber reinforced cement-based 3D printed composites

Continuous fiber reinforced cement-based composites (CFRCCs) 3D printing technology holds promise for fabricating intricate components with enhanced mechanical properties, demonstrating significant technical potential. However, for this emerging technology, the relationship between process parameters and the performance of printed specimens remains unexplored. This study developed a novel CFRCCs 3D printing system to investigate, for the first time, the effect of process parameters on forming quality and flexural strength. Quantitative indexes were proposed to evaluate the extrudability and buildability of CFRCCs 3D printing. The experimental results showed that the printed lace displayed consistent width without interruptions, showcasing strong extrudability. Continuous fibers enhanced shape retention and improved stability during layer-by-layer stacking, demonstrating excellent buildability. Additionally, a one-factor experiment investigated the impact of printing speed, pumping flow rate, layer thickness, and nozzle diameter on the flexural strength of 3D printed CFRCCs. The results highlight the significant influence of process parameters on the flexural strength of printed specimens, indicating the necessity of appropriate parameter selection during CFRCCs 3D printing. Notably, the flexural strength of continuous fiber reinforced specimens (0.0218 % fiber volume fraction) exhibited a 27.7 % increase compared to unreinforced specimens under identical process parameters.