Fineness, or particle size of portland cement affects hydration rate and thus the rate of strength gain. The smaller the particle size, the greater the surface area-to-volume ratio, and thus, the more area available for water-cement interaction per unit volume. The effects of greater fineness on strength are generally seen during the first seven days (PCA, 1988[1]).

一、 Standard Test Methods

•  AASHTO T 98 and ASTM C 115: Fineness of Portland Cement by the Turbidimeter.
•  AASHTO T 128 and ASTM C 184: Fineness of Hydraulic Cement by the 150-mm (No. 100) and 75-mm (No. 200) Sieves
•  AASHTO T 153 and ASTM C 204: Fineness of Hydraulic Cement by Air Permeability Apparatus
•  AASHTO T 192 and ASTM C 430: Fineness of Hydraulic Cement by the 45-mm (No. 325) Sieve