Cement products

What is it, cement?

Cement, this simple grey powder is an inorganic hydraulic binder, indispensable in the construction industry yet. When mixed with water it hardens through chemical processes, and this property it conserves even under water.

Components constituting the cement

Additives:

granulated blastfurnace slag

fly ash

pozzolana (trass)

ground limestone

Cements are grouped into different types depending on the proportion of the constituents.
Marking of the cements contains information about the types of cements according to standard MSZ EN 197-1:2000.

For marking the cements the following figures and letters are used:
CEM	-	cement
I	-	Portland cement without additives
II	-	composite Portland cement, containing some additive
III	-	blastfurnace slag cement
IV	-	pozzolanic cement
V	-	composite cement
A, B	-	giving information about the content of additive

The following letters designate the type of the additive:
S	-	granulated blastfurnace slag
V	-	fly ash
P	-	pozzolana (trass)
L	-	powdered limestone
M	-	composite (two or more additives e.g. fly ash "V" + powdered limestone "L"

Figures 32.5; 42.5 or 52.5 (MPa) represent typical 28-day strength values.

Classification of cements

Base for the classification of cements is their standard strength at the age of 28 days.

According to this criterion there are three classes by strength:

52,5 MPa

42,5 MPa

32,5 MPa

Based on their initial strength within each standard strength class two more classes are distinguished: N - meaning normal and R - meaning high initial strength.

Based on the additives the following cements are distinguished:

Portland cement (CEM I) - does not contain any additive

composite Portland cements (CEM II)

- blastfurnace slag Portland cement

- fly ash Portland cement

- pozzolanic Portland cement

- composite Portland cement

blastfurnace slag cement (CEM III)

pozzolanic cement (CEM IV)

composite cement (CEM V)

Based on specific properties (according to MSZ 4737-1, -2):

sulfate resistant Portland cement

sulfate resistant fly ash Portland cement

white Portland cement

Currently in Hungary 15-20 types of cement are being produced or sold.

Transportation

Cement is transported either in bulk form or packed into 25 and 50 kg paper bags (with valve) in unit batches weighing 1 to 1.5 ton, also on EUR pallets loaded onto road or railway transport vehicles.

Storage

Cements are - by their nature - susceptible to moisture. It is impossible to fully exclude the influence of humidity. Therefore, even when stored in dry places, after three months one has to reckon with some strength loss.

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