Abstract
The specific surface measured with Blaine air permeability apparatus, using Carman's equation, Eq. (3), decreases with the porosity of the powder bed as shown in Fig. 1.
(3)
In this paper, a method of determination of the specific surface not influenced by porosity adopted in the test is discussed for several sorts of cement and cement raw materials. The relation between porosity and the time required for air to pass through the powder bed is shown in Fig. 2, with conclusion that C and D in Eq. (6) are constants not influenced by the characteristics of powders.
(6)
Consequently, the specific surface not influenced by porosity adopted in the test is calculated from Eq. (7), though permeability can be tested at any porosity.
(7)
The graphical procedure of calculation is summarized in Fig. 3.
(Received May 4, 1964)
