超细粉对高性能超高泵送混凝土性能的影响研究

Effect of Superfine Powder on High Performance Super-high Pump Concrete Performance

采用不同超细粉配制高性能超高泵送C60混凝土,研究超细矿粉、超细粉煤灰及硅灰对C60混凝土性能的影响。结果表明:超细矿粉及硅灰均降低了混凝土的扩展度并延长了倒坍时间,超细粉煤灰则起到相反的作用,3种超细粉均降低了混凝土的压力泌水率。超细粉掺入后都提高了混凝土力学性能,其中掺超细矿粉及硅灰混凝土早期强度优于掺超细粉煤灰混凝土,但超细粉煤灰混凝土后期强度较好。超细粉促进了水化反应的进行,水泥石结构更加密实,孔隙率降低。掺入8%超细粉煤灰后,混凝土水化温升及自收缩均明显减小。

Different superfine powder was used to prepare C60 high performance pumping concrete to research the effects of superfine slag, fly ash and silica fume on C60 concrete. The results show that superfine slag and silica fume decrease the slump flow and extend the collapse time, and the superfine fly ash has opposite effect, and three kinds of superfine powder decrease the pressure bleeding rate. Superfine powder improves mechanical properties of concrete, and superfine slag and silica fume concrete early strength is higher than superfine fly ash, while the late strength of superfine fly ash is better than superfine slag and silica fume concrete. Superfine powder promotes the hydration reaction and the cement stone structure is more autogenous shrinkage and compact and lower porosity. After incorporation of 8% superfine ash, the hydration temperature rise are significantly reduced.