Low-alkali cements are Portland cements that contain a relatively small amount of sodium, potassium, or both. Portland cements with a total content of alkalies (Na2O equivalent) not above 0.6 percent. These are used in concrete made with certain types of aggregates that contain a form of silica that reacts with alkalies to cause an expansion that can disrupt a concrete.
Portland Composite Cements CEM II/A-M (P-LL) 32,5 R/N, CEM II/B-M (P-LL) 32,5 R/N and CEM II/A-M (P-LL) 42,5 R/N cement types :For producing CEM II/A-M (P-LL) 32,5 R/N, CEM II/B-M (P-LL) 32,5 R/N and CEM II/A-M (P-LL) 42,5 R/N cements, pozzolanas and limestone are added to clinker as additives. Pozzolanas is the most important natural pozzolanic material used as a cement additive.
Pozzolanas have the same features of Portland cement in terms of pressure resistance, setting period and volume expansion. (Resistance- 28 days: min. 42,5 Nt/mm2)
CEM I 42.5 R and CEM I 42.5 N: Cements are produced with clinker – 96% and 4% limestone. The limestone that is added during the grounding process adjusts the setting period. Final resistance (min. 42,5 Nt/mm2) is obtained at the end of 28 days for Portland cements. Increasing the resistance beyond this period is too few and slow.
CEM I 52.5 N: 95 to 100% clinker and auxiliary components between 0 and 5%. Calcium sulfate is added to adjust the setting time and is a rapid hardening cement for early strength or higher strength class.
White cement is manufactured with limestone, low iron content kaolin clay, and gypsum. It is used in architectural works requiring great brightness and artistic finishes to create mosaics and artificial granite, and for sculptural casts and other applications where white prevails.