Cement (Caementum)

The word cement is derived from the Latin word ement caementum ındaki, which means chipped stone crumbs. Then this word is used in the sense of binding.

Cement is a material whose main raw materials are limestone and clay and used for bonding mineral parts (sand, gravel, brick, briquette, etc.). In order for the cement to perform this bonding feature, water is absolutely required. Cement is a binder that hardens by reacting with water. Crushed limestone, clay and iron ore and / or sand, if necessary, are ground and ground into powder. This material is baked in rotary ovens at 1400-1500 ° C. The resulting product is called “clinker..

Then, some gypsum is added to the clinker (4-5%) and ground into very fine powder to obtain Portland Cement. In cement production with additives; other than clinker and gypsum, depending on the type of cement one or a few together trass, blast furnace slag, fly ash, silica fume, etc. solids. Cement is the component that occupies the smallest volume in most concrete mixtures; The most commonly used cement types are Portland Composite Cement, Additive Cement, Slag Cement and Sulfate Resistant Cement.

Since aggregate grains are the most robust elements in normal concrete, the other two elements (cement paste and adherence) determine the strength. The strength of the cement paste is highly dependent on the water / cement ratio.

Cement types used in concrete and conformity assessment are standardized in TS EN 197 series.

After the TS EN 197-1 standard was issued, all the old standards except the three special purpose cement standards were abolished. These three standards are TS 21 White Portland Cement, TS 22 Mortar Cement and TS 10157 Sulphate Resistant Cement standards. The equivalents of the general purpose cements that are repealed are covered by the new standard.

The new TS EN 197-1 standard ensures that more cement types can be used than the cement types currently used in concrete production in our country.

TS EN 197-1 marks cements in five main types, from CEM I (Portland Cement) to CEM V’e (composite cement). The marking includes: the main cement type; Portland cement clinker ratio; the second main component; standard (eg 28-day) strength class and early strength gain rate. For example, a Portland Slag Cement type is shown as follows: CEM II / A-S 42.5 N. Sub-class “N” indicates normal early strength, “R” indicates rapid early strength. Standard strength classes, Subtype, represent the second main component (blast furnace slag in this example). Portland cement shows the ratio of clinker as (A) high, (B) medium and (C) low.

Component Materials of Cement
main component, e.g. Portland cement clinker; the second main component, e.g. fly ash, blast furnace slag, limestone, silica fume; minor additive component, e.g. fly ash, blast furnace slag, limestone, natural puzzolan; socket adjuster, eg. calcium sulfate; chemical additives, e.g. pigments, air entraining additives.

The letters that indicate the second main component are:
S – blast furnace slag; D – silica fume; P – natural puzzolan; Q – natural calcined puzzolan; V – silissi fly ash; W – limestone fly ash; T – baked schist; M- Two or more of the above.