掺珍珠岩水泥石孔分形维数及其与孔结构、强度的关系

通过压汞法测试不同龄期掺0-40%珍珠岩掺合料水泥石的孔结构参数,利用分形理论的相关知识研究这些水化物的孔体积分形特征,计算它们的孔分形维数D=3.3～3.5,分析并探讨该水泥石孔分形维数与孔结构参数、抗压强度之间的关系.结果表明水泥石孔分形维数与孔隙率、孔径、孔表面积有密切的关系,随着孔分形维数增大,孔隙率提高,孔径扩大、孔表面积增大,孔结构就越劣化,对应的材料抗压强度下降.因此孔体积分形维数可用于综合评定材料的孔结构特性.

Research on Pore Volume Fractal Dimension and Its Relation to Pore Structure and Strength in Cement Paste with Perlite Admixture

By MIP(Mercury Intrusion Porosimetre) experiment pore structure parameters of Portland cement paste with 0-40% perlite admixture during 3 curing stages were determined and reported in this paper.Pore volume fractal feature was investigated with fractal theory and pore volume fractal dimensions D=3.3-3.5 were calculated in the cement-based materials.The relations of pore volume fractal dimension to pore structure in cement paste and compressive strength in mortar were analyzed and discussed in detail.The results show that there are close relations in linear equation between pore volume fractal dimension and pore structure parameters,such as porosity and pore special area.So is the compressive strength.With increasing of pore volume fractal dimension,porosity,pore special area and median pore diameter,pore structure is degraded and compressive strength is decreased correspondingly in cement paste.Therefore,it is finally concluded that pore volume fractal dimension can be used as comprehensive parameter to assess situation of pore structure for cement-based materials.