【摘要】 为了探究蒸汽养护制度对超高性能混凝土(UHPC,>200 MPa)性能的影响，研究了5种不同养护制度(标准养护7 d、60℃蒸汽养护3和7 d、90℃蒸汽养护3和7 d)对UHPC早期力学性能、水化产物和微观结构的影响.结果表明：UHPC的抗压强度和初始开裂拉伸应力与蒸汽养护温度和时间呈正相关；但抗折强度、极限拉伸应力和极限拉伸应变表现出先提高后降低的趋势.物相分析和同步热分析表明，蒸汽养护加速了UHPC中水泥熟料的水化反应，氢氧化钙含量明显降低，生成更多的C-S-H凝胶，使UHPC早期的微观结构更加密实.此外，蒸汽养护增强了水泥浆体与骨料和纤维的界面过渡区，从而提高了UHPC的早期力学性能.更多还原

【Abstract】 The effects of five different curing regimes(standard curing for 7 d, 60 ℃ steam curing for 3 and 7 d, and 90 ℃ steam curing for 3 and 7 d) on the early mechanical properties, hydration products and microstructure of ultra-high performance concrete(UHPC, >200 MPa) were investigated to explore the effect of steam curing regimes on the performances of UHPC. The results indicate that the compressive strength and initial crack tensile stress of UHPC are positively correlated with steam curing temperature and time. However, the flexural strength, ultimate tensile strength, and ultimate tensile strain capacity show a trend of first increasing and then decreasing. The phase analysis and simultaneous thermal analysis show that steam curing accelerates the hydration reaction of cement clinker in UHPC. It is found that the calcium hydroxide(CH) content is significantly reduced, meaning that more calcium-silicate-hydrate(C-S-H) gels are generated. As a result, the early microstructure of UHPC is more compacted. Moreover, steam curing enhances the interface transition zone between cement paste and aggregates and fibers, thereby improving the early mechanical property of UHPC.更多还原