Material-Characteristics of Binder-Jet 3D Printed Hydrated CSA Cement with the Addition of Fine Aggregates (2019-02)¶

Recent advances in additive manufacturing technologies for cementitious construction have mainly focused on low resolution fused deposition methods, herein the authors aim to advance high resolution binder jet printing methods. The inherent challenge of additive binder jet cement-based printing is to achieve adequate mechanical strengths and maintain geometry without the agitation and casting of conventional fabrication. The authors utilize a commercially available binder jet printer to fabricate sample specimens that are used to assess material and geometric properties. A novel water-based binder formulation, compatible with concrete chemistry and piezoelectric jetting, is developed. This study examines a dry cementitious mix comprised of round grain fine aggregates and calcium sulfoaluminate (CSA) cement. The printed samples have a density of 1474–1501 kg/m3, 28-day compressive strengths of 5.94–6.70 MPa, and flexural strengths of 1.76–2.39 MPa. The results indicate that binder jet printed CSA cement with the addition of fine aggregates possess the strength and the resolution to produce high detail objects with rapid production capability and compatibility in applications with conventional construction materials.