Development of Green Engineered Cementitious Composite using Fly Ash and Nanosilica for 3D Printing

The effects of adding Nanosilica (NS) to Engineered Cementitious Composites (ECC) for 3D Printing (3DP) applications were investigated in this study. The mechanical characteristics of 3DP ECC mortar with different NS contents were investigated. The basic components of the composite included fly ash, M-sand, polypropylene fibers, Ordinary Portland Cement, nanosilica and an accelerator. There were four different mix proportions of NS involving 0.05%, 0.1%, 0.15%, and 0.2%. After 3, 7, 14, and 28 days of curing, the following strengths, viz., pull-out strength, direct tensile strength, compressive strength, and flexural strength were assessed. Addition of NS improved the mechanical properties of ECC up to an ideal level of 0.15%, after which decreasing returns and adverse effects, including agglomeration, were observed. Insights into the ideal NS content for obtaining maximum performance of ECC obtained from the study provide knowledge for formulations in high-performance 3DP technologies.