不同方式养护高强水泥基材料孔表面积分形维数与孔结构的关系

Relationship between Pore Surface Fractal Dimension and Pore Structure of High Strength Cementitious Materials Cured by Different Methods

采用压汞法测定了不同龄期及不同养护方式的高强水泥基材料的孔结构,基于孔表面积分形模型计算得到了高强水泥基材料的孔表面积分形维数,并探讨了孔表面积分形维数与孔隙率、平均孔径、中值孔径、孔表面积、孔径分布及养护方式和龄期的关系。结果表明:高强水泥基材料的孔结构具有明显的分形特征,孔表面积分形维数在2.7~2.8之间;孔表面积分形维数与高强水泥基材料的抗压强度和孔隙率的相关性较差;孔表面积分形维数越大,高强水泥基材料的孔径越大,孔表面积越大,小于20 nm和大于100 nm的孔越少;随着龄期的增加,孔表面积分形维数增加;与标准养护相比,热水养护和蒸汽养护降低了孔结构的复杂性。

Pore surface fractal dimension of high strength cementitious materials at different ages and different curing methods, and its pore surface fractal dimension was determined by mercury intrusion porosimetry. Pore fractal model was used to calculate pore surface fractal dimension of high strength cementitious materials. The relationship between pore surface fractal dimension and porosity, average pore diameter, median pore diameter, pore surface area, pore size distribution and curing methods of high strength cementitious materials were investigated. Results indicate that pore structure of high strength cementitious materials has occupied excellent fractal properties and the values of fractal dimension are between 2.7 and 2.8. Pore surface fractal dimension has poor correlation with compressive strength and porosity. The higher pore surface fractal dimension is, the higher pore diameter and pore surface area are, but the smaller pore structure between lower than 20 nm and more than 100 nm becomes. Pore surface fractal dimension increases with ages. In addition, hot water curing and steam curing reduced the complexity of pore structure compared to standard curing.