It is a material used for bonding gravel, bricks, briquettes and others, the main raw materials of which are limestone, clay and mineral parts. The cement must be mixed with water for the reaction.
Limestone, clay, iron ore, sand are crushed into a powder. This material is then baked in rotating ovens at 1400-1500°C. This resulting product is called "clinker".
Portland cement is obtained by grinding into a very fine clinker powder (4-5%), to which a small amount of gypsum is added. Production of alloyed cement (materials vary depending on the type of cement.) materials used for clinker, gypsum, blast furnace slag, ash, silica, etc.
The smallest part of the volume in the concrete mix is occupied by cement. The preferred types of cement according to its characteristics are Portland cement, alloyed cement, slag cement and sulphate cement, except for special purposes when white Portland cement and some other types of cement are used.
Inert fine-grained elements are the most durable in conventional concrete. These elements determine the strength and adhesion of the cement mixture. The strength of the cement mixture depends on the ratio of components. The types of cement used in concrete are standardized in the TS EN 197 series.
Part 1: Cement, composition, properties and acceptance criteria ;
Part 2: conformity assessment.
After the TS EN 197-1 standard came out, all the old standards, except for three special purpose ones, were canceled. These three standards are TS 21 white Portland cement, TS 22 cement, and TS 10157 sulfate-resistant cement. The equivalents of cancelled General-purpose cements have been replaced by a new standard (table 1).
The new TS en 197-1 standard guarantees that more types of cement can be used in our country than the types of cement currently used in concrete production.
TYPES OF CEMENT
Marking of cement
TS EN 197-1 specifies five main types of cement: from CEM I (Portland cement) to CEM V (composite cement). The marking includes: the main type of cement; the ratio of portland cement clinker; the second main component; the standard (for example , 28-day) strength class.
For example, the type of portland slag cement is classified as follows:
CEM II / A-S 42.5 N
Subclass " N "shows normal strength,” R" shows fast strength.
Standard strength classes.
The subtype shows the second main component (the slag in this example).
It shows the ratio of portland cement clinker as (a) high, (B) medium, and (C) low.
Main type of cement
Component compositions of cement
According to the different types of cement in TS EN 197-1 shown in table 1, the composite materials of cement are as follows:
The main component, for example. Portland cement clinker;
The second main component, such as blast furnace slag, limestone, and silica;
Low amount of additional components, such as ash, blast furnace slag, limestone;
Chemical additives or pigments.
The components of the cement
C-Blast Furnace Slag;
K-Natural calcined pozzolan;
M-two or more of the above.