摘要
采用自行设计的立式千分表架,研究了不同水胶比（0.16、0.20和0.24）、不同砂率（0.4、0.5和0.6）和不同钢纤维体积掺量（0%、1%、2%和3%）对超高性能水泥基复合材料（Ultra-High Performance Cementitious Composites,UHPCC）自成型后1 d后自收缩特性的影响,同时结合综合热分析、压汞法微观分析技术对自收缩机理进行探讨。结果表明：UHPCC自收缩随着水胶比的降低而增加,当水胶比从0.24分别减小到0.20、0.16时,60 d自收缩值分别增加了14.4%和25.4%;短细钢纤维对于UHPCC自收缩的抑制作用不明显;水胶比降低,非蒸发水含量降低,水化程度减小,但水胶比降低使5~50 nm毛细孔体积分数增多,自干燥效应增加,对于自收缩而言是负效应,对比可知自干燥效应在自收缩影响因素中占有主导地位。
The self-designed vertical dial gauge holder was used in this paper. The influence factors of autogenous shrinkage of UHPCC, which include different water-binder ratios, different sand ratios, fraction process of steel fiber, were mainly studied, combined with thermal analysis and mercury method microscopic analysis techniques to explore the mechanism of autogenous shrinkage. The results showed that autogenous shrinkage of UHPCC increases with the decreasing of water-binder ratio. The autogenous shrinkage of 60 d increases by 14.4% and 25.4% , when the water-binder ratio decreases from 0.24 to 0.20, 0. 16, respectively. Fine steel fibers have no obvious effects on the autogenous shrinkage of UHPCC. Non-evaporable water content decreases with the decreasing of water-binder ratio, which is positive effect on the autogenous shrinkage. However, the volume fraction of pores with the size range from 5 to 50 nm increases with the decreasing of water-binder ratio, which is negative effect on the autogenous shrinkage. Self-dessication effect is dominant factor in the autogenous shrinkage.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2015年第3期813-818,823,共7页
Bulletin of the Chinese Ceramic Society
关键词
超高性能水泥基复合材料
自收缩
水胶比
非蒸发水含量
孔结构
utra-high performance cementitious composites
autogenous shrinkage
water-binder ratio
non-evaporable water content
pore structure
