Maroszek Marcin, Hager Izabela, Mróz Katarzyna, Sitarz Mateusz, Hebda Marek
Department of Materials Engineering, Faculty of Materials Engineering and Physics, Cracow University of Technology, Warszawska 24, 31-155 Kraków, Poland.
Chair of Building Materials Engineering, Faculty of Civil Engineering, Cracow University of Technology, Warszawska 24, 31-155 Kraków, Poland.
Materials (Basel). 2025 Aug 15;18(16):3845. doi: 10.3390/ma18163845.
Three-dimensional concrete printing (3DCP) is an emerging additive manufacturing technology with increasing application potential in the construction industry, offering advantages such as reduced labor requirements, shortened construction time, and material efficiency. However, structural integrity remains a challenge, particularly due to weak interlayer bonding resulting from the layered manufacturing process. This study investigates the mechanical performance and anisotropy of 3D-printed mineral-based composites with respect to the time interval between successive layers. Specimens were printed with varying interlayer intervals (0, 25, and 50 min) and tested in different loading directions. Flexural, compressive, and tensile strengths (direct and splitting methods) were measured both parallel and perpendicular to the layer orientation. Results showed a clear degradation in mechanical properties with increasing interlayer time, particularly in the direction perpendicular to the layers. Flexural strength decreased by over 25% and direct tensile strength by up to 40% with a 25 min interval. Compressive strength also declined, though less dramatically. Compared to cast specimens, printed elements showed 3-4 times lower compressive strength, highlighting the significant impact of interlayer cohesion. This study confirms that both the time between layers and the loading direction strongly influence mechanical behavior, underlining the anisotropic nature of 3DCP elements and the need for process optimization to ensure structural reliability.
三维混凝土打印（3DCP）是一种新兴的增材制造技术，在建筑行业的应用潜力日益增大，具有减少劳动力需求、缩短施工时间和提高材料效率等优势。然而，结构完整性仍然是一个挑战，特别是由于分层制造过程导致的层间粘结薄弱。本研究针对连续层之间的时间间隔，研究了3D打印矿物基复合材料的力学性能和各向异性。采用不同的层间间隔（0、25和50分钟）打印试件，并在不同加载方向进行测试。在平行和垂直于层方向上测量了弯曲、压缩和拉伸强度（直接法和劈裂法）。结果表明，随着层间时间增加，力学性能明显下降，尤其是在垂直于层的方向上。层间间隔为25分钟时，弯曲强度下降超过25%，直接拉伸强度下降高达40%。抗压强度也有所下降，不过降幅较小。与浇筑试件相比，打印构件的抗压强度低3至4倍，突出了层间粘结的重大影响。本研究证实，层间时间和加载方向都会强烈影响力学行为，强调了3DCP构件的各向异性本质以及优化工艺以确保结构可靠性的必要性。
