多孔混凝土孔隙的表征及其与渗透性的关系研究

Pore representation and the relationship between pore and permeability of the porous concrete

分别研究了单掺粉煤灰、矿渣和硅灰3种矿物掺合料的多孔混凝土有效孔隙率与目标孔隙率之间的关系,并探讨了掺有矿物掺合料时多孔混凝土有效孔隙率、透水系数、平面孔隙率、等效孔径和抗压强度之间的关系以及等效孔径大小的分布情况。试验结果表明：采用绝对体积法能有效控制多孔混凝土的孔隙率,不同掺合料的多孔混凝土有效孔隙率与透水系数之间存在相关性良好的二次函数关系,与抗压强度基本成反比例关系,并据此得出对应关系式。等效孔径的大小和孔隙的个数影响着平面孔隙率变化。分别单掺粉煤灰、矿渣和硅灰且有效孔隙率在20%~30%的多孔混凝土,其等效孔径大小在10~20 mm之间,其中主要范围集中在13~16 mm。在此范围内,多孔混凝土的透水系数增幅最大。

Relationship between the valid porosity and anticipate porosity of three different mineral admixtures i.e.fly ash, slag and silica fume of the porous concrete is studied respectively.The relationship among the valid porosity, permeability coefficient, plane porosity, equivalent aper- ture and compressive strength and the situation of pore distribution is also discussed.The results show that it can effectively control the porosity of the porous concrete by adopting absolute volume method.Among the different mineral admixture,the valid porosity and permeability coefficient exists nicer quadratic function relationship, the valid porosity and permeability coefficient basically becomes inversely-proportional relationship, which could get the correlative relational equation.The size of equivalent aperture and the number of the pores influence the change of the plane porosity.When the valid porosity of the different minera! admixtures porous concrete are from 20% to 30% ,the size of the equivalent aperture ra- dius is from 10mm to 20mm.Furthermore,the main size is from 13mm to 16mm,in which range,the increasing amplitude of the permeability co- efficient achieves the maximum value.