高强大流动度混凝土黏度影响因素研究

The influence of multiple factors on the viscosity of concrete with high strength and fluidity

研究了矿物掺合料种类和掺量、砂率、粗骨料级配等因素对高强大流动度混凝土黏度的影响规律。试验结果表明,10%掺量的粉煤灰、超细石灰石粉、超细石英粉3种矿物掺合料均可显著降低混凝土黏度;相同工作性能时,粉煤灰降黏效果优于相同掺量的超细石灰石粉与超细石英粉。超细石灰石粉与超细石英粉对高强混凝土的降黏效果随掺量增加更加显著,掺合料复掺对高强混凝土的降黏效果更佳。对于高强混凝土黏度调控,具有最佳砂率和最佳粗骨料级配。掺加一定量的硅灰,可以优化混凝土中浆体对骨料的包裹性。

The influence of type and amount of supplementary cementitious materials, sand/total aggregate ratio and coarse ag- gregate gradation on the viscosity of concrete with high strength and fluidity was studied. Results show that fly ash,superfine cal- cite and superfine silica at a replacement level of 10% can reduce the viscosity of concrete significantly. Moreover, for a same con- tent,fly ash is most effective in decreasing the viscosity of concrete. The viscosity reducing ability of superfine calcite and su- perfine silica is increased with their content. The combined usage of superfine calcite and silica brings better effect on viscosity reducing of high strength concrete. It is also found that there is an optimum value of sand/total aggregate ratio and coarse aggre- gate gradation for regulating the viscosity of high strength concrete. Besides,the addition of certain amount silica fume can refine the workability of concrete.