THE EFFECT OF SIZE OF GRAIN UPON THE PROPERTIES OF SILICA CEMENT1

A thorough study has been made of the effect of size of grain upon the softening point and linear change of silica cements prepared in the laboratory. The ratio of grain sizes in a cement of constant chemical composition has a distinct effect upon the softening point. The linear change after heating to 110°C and 1300°C was not appreciably affected by variation in grain size. From data obtained by testing a large number of commercial cements it is concluded that, owing to variations in clay content, screen analyses are not definitely related to rate of settle or to softening point. A method for determining “rate of settle” is described.