3D打印锑尾矿UHPC力学性能研究
Study on Mechanical Properties of 3D Printing Antimony Tailings UHPC

为了响应“低碳”战略，推动混凝土结构的高质量发展，超高性能混凝土(UHPC)应运而生，成为上世纪末期兴起的一种创新水泥基复合材料。UHPC以其出色的力学性能、卓越的耐久性和优异的工作性而著称。3D打印砼技术由于设计灵活性、减少材料浪费、高产性等优点在国内外建筑工程领域崭露头角。本研究将锑尾矿以0%、10%、20%、30%、40%、50%掺量作为细骨料掺入UHPC中，采用新型的3D打印技术研究锑尾矿对3D打印UHPC在14天与28天的三向抗压与抗折强度的影响。此外，还研究了不同比例锑尾矿对3D打印UHPC各向异性的影响规律。结果表明，锑尾矿增强了3D打印UHPC的早期和晚期强度。当锑尾矿掺量为40%时，三向抗压强度分别达到了123.4 MPa、125.8 MPa、135.5 MPa。相较于未掺锑尾矿的基准组，强度提高了11.7%。锑尾矿可以弱化早期抗压强度的差异率，但是在终期强度上却影响偏大。早期抗折强度变化率与终期各向异性的变化趋势大体一致且始终保持在非常低的水平。
In order to respond to the “low-carbon” strategy and promote the high-quality development of concrete structures, Ultra-High Performance Concrete (UHPC) emerged as times required and became an innovative cement-based composite material that emerged at the end of the last century. UHPC is known for excellent mechanical properties, excellent durability and exceptional workability. 3D printing concrete technology is emerging in the field of construction engineering at world due to design flexibility, reduction of material waste and high yield. In this study, antimony tailings were incorporated into UHPC with 0%, 10%, 20%, 30%, 40% and 50% content as fine aggregate, and a new 3D printing technology was adopted to research the influence of antimony tailings on the three-way compressive and flexural strength of 3D printing UHPC at 14 days and 28 days. In addition, the different proportion of antimony tailings was studied in the influence law of 3D printing UHPC. The results showed that antimony tailings enhanced the early and late strength of 3D printing UHPC. When the content of antimony tailings is 40%, the three-way compressive strength reaches 123.4 MPa, 125.8 MPa and 135.5 MPa respectively. Compared with the base group of undoped antimony tailings, the strength is increased by 11.7%. Antimony tailings weaken the difference rate of compressive strength in the early stage, emerging with a greater effect on the final strength. The change rate of flexural strength in the early stage was consistent with the change trend of anisotropy in the final stage and remained at a very low level.