水泥-白云石粉胶凝材料孔结构研究

Study on the Pore Structure of the Cement-Dolomite Powder Cementing Material

采用吸水动力学法测试水泥-白云石粉胶凝材料孔结构,分析其孔结构与强度的相关性。结果表明,白云石粉适量取代水泥可改善水泥胶凝材料平均孔径,提高抗压强度,但对其孔径均匀性不利。当白云石粉掺量为5%时,胶凝体系的3 d平均孔径较未掺时减小7.29%,抗压强度提高3.10%,孔径均匀性降低6.68%。白云石粉掺量增加使水泥-白云石粉胶砂试样平均孔径呈先减小后增大趋势,掺量为5%时,胶砂平均孔径最小。随白云石粉掺量增加,水泥-白云石粉胶砂试样孔均匀性先降低后提高,掺量为5%胶砂孔均匀性最差。水泥-白云石粉胶砂试样抗压强度与其平均孔径随石灰粉掺量变化规律具有较好的负相关性,平均孔径增大则强度降低。

The pore structure of cement-dolomite powder cementing material was tested by water absorption dynamic method,and the correlation between pore structure and strength was analyzed.The results showed that,the average pore size and the compressive strength of cementitious materials could be improved by adding appropriate amount of dolomite powder,but it was not good for the pore size uniformity of cementitious materials.When the content of dolomite powder was 5%,the 3 d average pore size of cementitious system was reduced by 7.29%,the compressive strength was increased by 3.10%,and the pore size uniformity was reduced by 6.68%compared with no doping.With the increase of dolomite powder content,the average pore diameter of cement-dolomite powder mortar samples decreased first and then increased.The average pore size of mortars with 5%dolomite powder was the least.With the increase of dolomite powder content,the pore uniformity of cement-dolomite powder mortar samples firstly decreased and then increased.The pore uniformity of mortars with 5%dolomite powder was the worst.There was a good negative correlation between the compressive strength and its average pore size of cement-dolomite powder with the addition of lime powder,that is,the strength decreased when the average pore size increased.