钢纤维搭配对超高性能混凝土拌合物性能的影响
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关键词：
超高性能混凝土；长短钢纤维；流变性能；力学性能
Key words：
UHPC; Long and short steel fiber; Rheological properties; Mechanical properties
刊期：
２０19年第1期
DOI：
10.19761/j.1000-4637.2019.01.055.06
文章编号：
基金项目：
作者：
高育欣，沈 锐，程宝军，麻鹏飞，完么东智
单位：
中建西部建设建材科学研究院，成都 610000
摘要
摘 要：通过设计不同水胶比、钢纤维掺量下超高性能混凝土（UHPC）配合比，比较了T200与min-v漏出时间和流动度的关系，发现T200能较好反映UHPC黏度的变化，与流动度共同表征UHPC的流变性能。采用较短纤维替代长纤维，其质量比小于0.75时，随着短纤维的加入能降低UHPC的黏度；当超过0.75后，长短钢纤维的“墙体效应”作用对流动度的贡献作用降低明显。长短纤维搭配能提高UHPC的综合性能。随着纤维影响因素（k）的增加，流动度先增加后降低；k值的变化与抗压强度和抗折强度呈良好的线性关系。
Abstract: By designing the ratio of ultra high performance concrete(UHPC) under different water-to-binder ratio and steel fiber content, the relationship between T200 and min-v leakage time and fluidity was compared. It was found that T200 can better reflect the change of UHPC viscosity. T200 and fluidity can reflect the rheological properties of UHPC. Short fiber was used to replace long fiber. When the mass ratio of long fiber and short fiber is less than 0.75, the viscosity of UHPC can be reduced with the addition of short fiber. When it exceeds 0.75, the effect of wall effect of long and short steel fiber on fluidity is obviously reduced. The combination of long and short fibers can improve the overall performance of UHPC. With the increase of fiber influencing factor(k), the fluidity increases first and then decreases; the change of k value has a good linear growth relationship with compressive strength and flexural strength.
结论
（1）T200和流动度可较好地反映UHPC的流变性能；6 mm钢纤维对13 mm和19 mm钢纤维的部分替代，降低了UHPC的黏度，提高了UHPC的工作性；在较短纤维替代长纤维的比例为0.75时，拌合物的流动度最大，黏度最小，对抗压强度降低小于10%，抗折强度降低小于25%。
（2）短纤维和长纤维混掺能够相互阻碍其旋转，减少浆体流动的阻碍，增加工作性；但当13 mm钢纤维替代19 mm钢纤维比例为0.75时，其“墙体效应”作用效果不明显。
（3）随着k值的增加，流动度先增加后降低；k值的变化与抗压强度和抗折强度呈良好的线性增长关系。
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引用本文
高育欣,沈锐,程宝军,等.钢纤维搭配对超高性能混凝土拌合物性能的影响[J].混凝土与水泥制品,2019(1):55-60.
GAO Y X,SHEN R,CHENG B J,et al.The Influence of Steel Fiber Mixing on Properties of UHPC Mixture[J].China Concrete and Cement Products,2019(1):55-60.
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