The properties were studied of Portland and slag mixedcements containing admixtures of 5 to 30 wt.% of ground limestone (asreplacement of cement) with a specific surface area of 400 to 900 m2kg-1. The decrease in strength in terms of increasing limestonecontent indicates that the limestone does not take part in cement gel formation.However, it is theoretically possible to prepare, from slag cement SPC 325 and10-12 wt.% ground limestone with a specific surface area of 550 m2 kg-1,a mixed cement exhibiting higher 2-day and 7-day strengths, and a 28-daystrength reduced by max. 10 % (compared to the original SPC 325 cement).
