Study on autogenous shrinkage characteristic and mechanism of ultra-high performance cementitous composite

2017 5th International Conference on Mechanical Engineering, Materials Science and Civil Engineering

机械制造;材料科学;土木建筑工程

Caixia, Li^1 ; Zhilin, Sun^2 ; Liqi, Yang^3 ; Guorong, Zhang^4,5

Zhangye Municipal Government and Social Capital Cooperation Management Center Office, Zhangye, China^1

Zhangye Traffic Construction Investment Co., Ltd., Zhangye, China^2

Chengde Road and Bridge Construction Corporation, Chengde, China^3

JSTI Group, Nanjing, China^4

State Key Laboratory of Safety and Health for In-service Long Span Bridges, Nanjing, China^5

关键词: Autogenous shrinkage;    Binder-aggregate ratio;    Coarse aggregates;    Dominant factor;    Evaporable water;    Structure analysis technique;    Ultra high performance;    Water binder ratio;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/324/1/012037/pdf
DOI  :  10.1088/1757-899X/324/1/012037

来源: IOP

【 摘 要 】

The self-designed vertical dial gauge holder was used in this paper. The influence factors of autogenous shrinkage of UHPCC, which include water-binder ratios, binder-aggregate ratios, sand ratios and fraction process of steel fiber, were mainly studied. The mechanism of autogenous shrinkage is explored by thermal analysis and pore structure analysis techniques. The results show that autogenous shrinkage of UHPCC increases with the decreasing of water-binder ratio. The autogenous shrinkage of 60d increases by 14.4% and 25.4%, when water-binder ratio decreases from 0.24 to 0.20, 0.16, respectively. Coarse aggregate has great positive effects on the autogenous shrinkage of UHPCC. 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.