低孔隙率胶凝材料的孔结构测定方法

本文用压汞法和氦比重仪法测定了低孔隙率胶凝材料的孔结构,结果表明氦孔隙率显著大于汞孔隙串。用两种方法测得的孔隙率与力学性能相关,得到完全不同的拟合参数。在低孔隙率胶凝材料中,大量闭合孔的存在使压汞法出现大的“损失孔隙”。因此,氦孔隙率可以作为低孔隙率胶凝材料的结构参数,而用压汞法可能会导致错误的结论。

STUDY ON THE MEASURING METHOD OF PORE STRUCTURE OF LOW-POROSITY CEMENTITICUS MATERIALS

The pore structures of low-porosity cementitious materials were determined by high mercury intrusion method and helium pycnometer method. The results show that the helium porosity is evidently greater than mercury porosity. Different regression constants were obtained with these two porosity values from the above methods. A great number of the "close pores" are present in low-porosity cementitious materials, which can cause the mercury intrusion method to lose the "missing porosity". Therefore, helium porosity may be used as a structural parameter for low-porosity cementitious materials, but an incorrect conclusion may be drawn if mercury porosity is used.