An Experimental Study on Separately Ground and together Grinding Portland Slag Cements Strength Properties

In this experimental study 7 and 28 day compressive, flexural strength and slag activity indices of Portland cement control and Portland slag cement were determined experimentally. The results of this study showed that the grinding time required for slag particles are higher than portland cement clinker particles for all the tested Blaine fineness values; therefore, the grind ability of the slag is observed to be lower than the grind ability of the clinker. The results indicated that the increasing the Blaine fineness values of the mortar mixes improved both the 7-day and 28-day slag activity indices. This means that in order to increase the quality of the slag, the granulated blast furnace slag particles should be ground to much finer. Together grinding Portland slag cements show higher strength values than the separately ground ones for the Blaine fineness values of 3000 cm 2 /g and 3500 cm 2 /g at 2 and 7 days. However, for Blaine fineness values of 4000 cm 2 /g and 4500 cm 2 /g, the separately ground Portland slag cements have higher strength values than the Together grinding ones at 2 and 7 days. For 28 days, the flexural strength of the Together grinding Portland slag cements show more or less the same values with the separately ground ones for all of the Blaine fineness values. Finally, the flexural strength of the separately ground Portland slag cements show higher values than the Together grinding ones again for all of the Blaine fineness values at 90 days.