Different saturated surface dry methods,namely pre-wetting saturated surface dry and saturated surface dry by adding extra water,were used,and ultra high performance concrete(UHPC)was prepared by replacing 50%river sand with recycled fine aggregate(RFA).The effect of saturated surface dry RFA obtained by different methods on the compressive strength,internal relative humidity and autogenous shrinkage of UHPC was studied,and the mechanism was explained by mercury intru-sion porosimetry test.The results show that when the total water-binder ratio is 0.24,compared to UHPC with pre-wetting saturated surface dry RFA,the UHPC with extra water saturated surface dry RFA has an increase in the volume of pores larger than 50 nm,and its compressive strength decreases.Its internal relative humidity decreases and its autogenous shrinkage increases.Its compressive strength of UHPC at age of 28.0 d is only reduced by 3.2%,and its autogenous shrinkage at age of 7.0 d is only increased by 10.5%.Therefore,in the actual project UHPC can be used to saturated surface dry RFA in order to obtain better construction benefits.
关键词
超高性能混凝土/饱和面干/再生细骨料/自收缩/内部相对湿度
Key words
ultra high performance concrete/saturation surface dry/recycled fine aggregate/autoge-nous shrinkage/internal relative humidity
维普
万方数据