A NEW METHOD OF EVALUATING THE ACTIVITY OF GROUND GRANULATED BLAST-FURNACE SLAG

Mortar specimens for compressive strength tests were prepared using six kinds of ground granulated blast-furnace slags of various Blame specific surface areas. Water-cement ratio and sand-cement ratio of base mortar containing no ground slag were fixed at 0.50 and 2.50, respectively. Replacement ratios of cement by ground slag were set at 30, 50 and 70% by volume. Both the preparation and moist-curing of the specimens were conducted at a constant temperature; i. e., 5, 10, or 20°C. The results of compressive strength test were analyzed to derive equations, by which the effects of each influential factor could be quantitatively evaluated. New two indices, which are independent on various factors, were proposed for evaluating the activity of ground slags.