纳米二氧化硅透水混凝土新拌流变及硬化性能

Rheological and Hardened Properties of Nanosilica Blended Pervious Concrete

关键词:  透水混凝土  纳米二氧化硅  工作性能  抗压强度  透水系数

Key words:  pervious concrete  nanosilica  workability  compressive strength  hydrological permeability

摘要:

针对传统透水混凝土工作性能不佳和强度偏低的问题，研究了纳米二氧化硅改性透水混凝土的新拌流变性能与硬化性能.结果表明：纳米二氧化硅能够改善新拌透水混凝土中浆体的黏聚性并减少振动时浆体的向下流动，当纳米二氧化硅质量分数达到100%时，透水混凝土中浆体的塑性黏度和触变环面积分别提高了6474%和23596%；纳米二氧化硅能够通过提高浆体强度来改善透水混凝土的抗压强度，当纳米二氧化硅质量分数超过050%后，其对透水混凝土抗压强度的增强效果不再明显；纳米二氧化硅还可以略微提高透水混凝土的透水性能，推测与纳米二氧化硅使得透水混凝土在竖直方向上的孔隙均匀分布有关.

Abstract:

Considering the poor workability and strength of traditional pervious concrete, nanosilica blended pervious concrete was prepared to study the influence of nanosilica on fresh and hardened properties of pervious concrete. The results show that nanosilica can improve cohesion of fresh cement paste in pervious concrete, preventing it from flowing downward. The rheological test results show that plastic viscosity will be increased by 6474% with 100% mass fraction of nanosilica and thixotropic loop area will reach 23596%. Compressive strength of pervious concrete can be improved via getting higher strength paste with nanosilica, however, no obvious increase of pervious concrete strength observed when the mass fraction of nanosilica exceed 050%. Slightly better connected porosity and hydrological permeability are achieved in the presence of nanosilica, which may be ascribed to the more uniform distribution of paste and pore in the vertical direction in pervious concrete with nanosilica.