摘   要：针对天山胜利隧道TBM压注式超高性能混凝土（UHPC）的性能要求，基于紧密堆积理论，优化了混凝土中胶凝材料各组分的比例。通过掺入钢渣粉、纳米早强剂和塑性膨胀剂配制出了大流动度、超长保坍、超早强、低收缩的UHPC，并研究了胶凝材料体系紧密堆积孔隙率、钢纤维掺量、混凝土流动性三者之间的关系。结果表明：采用复合掺合料、钢渣粉优化胶凝体系、骨料体系可制备出工作性良好、各项性能指标均能满足要求的UHPC，初始流动度大于700 mm，4 h流动度经时损失小于5%，1 d拆模且抗压强度大于设计要求51.6 MPa，28 d干燥收缩仅为200×10^-6。纳米早强剂的掺入不但保证了混凝土早期强度的增长，而且不影响混凝土流动性的长时间保持和后期强度的增长。

Abstract: According to the performance requirements of TBM pressure-pumping ultra high-performance concrete (UHPC) in Tianshan Shengli Tunnel, based on the compact packing theory, the proportion of each component of the cementitious material system in the concrete was optimized. The plastic expansion agent UHPC with high fluidity, ultra-long time slump retention, ultra-early strength and low shrinkage was prepared by adding steel slag powder, nano early strength agent. The relationship between the tightly packed porosity of the cementitious material system and the steel fiber content and concrete fluidity was researched. The results show that the use of compound admixtures, steel slag powder, aggregate system to optimize the cementing system materials can prepare UHPC with excellent working performance and all performance indexes can meet the requirements. The initial fluidity is greater than 700 mm and the 4 h fluidity loss is less than 5%, 1 d demolding and compressive strength is greater than the design requirements of 51.6 MPa, 28 d drying shrinkage is only 200×10^-6. The incorporation of nano early strength agent not only guarantees the increase of the concrete’s ultra-early strength, but also has no effect on the concrete’s long-term retention of fluidity and the growth of its strength in the later period.