Cement: Types Of Cement, Composition, and Usage

What is Cement?

The Portland cement was first manufactured by Joseph Aspdin from England who was a bricklayer and building contractor. He took the license for Portland cement in 1824. Since then, continuous efforts were made on cement and discovered that improving chemical compositions in cement show different characteristics and properties.

Cement is a binder, a material used for construction that sets, hardens, and adheres to different materials to bind them with each other. Cement is seldom used by itself but rather to bind sand and gravel together. Cement is a fine mineral powder produced with very proper procedures. When mixed with water, this powder changed into a paste that binds and sets, because the composition and fineness of the powder may differ. Cement has various properties basing on its make-up.
Cement is a great adhesive that is used to bind sand and aggregates to make concrete, one of the most useful building materials. Cement is manufactured by mixing calcium, silicon, aluminum, iron, and other components (normally limestone, shale, and clay) in a chemical reaction to produce clinker, which is then ground into a fine powder (microns) and blended with ground gypsum and other ingredients to make cement.

Types of Cement

Cement is mainly defined into two types depending on the hardening and setting mechanism.

  • Hydraulic Cement
  • Non-hydraulic Cement

Hydraulic cement

The cement which sets in the presence of water is called hydraulic cement. Due to the chemical reaction of cement and water, is called Hydration. Limestone, clay, and gypsum are the main raw material to produce hydraulic cement. This raw material is burned at a very high temperature to produce Hydraulic Cement. Portland cement is the best example of hydraulic cement.

Non Hydraulic cement:

The non-hydraulic cement doesn’t need water to get harden. This type of cement sets when it reacts with the carbon dioxide from the air. This cement is resistant to attack by chemicals after setting. Non-hydraulic cement is produced utilizing non-hydraulic lime, gypsum plasters, and oxychloride, which has liquid properties.

Non-Hydraulic-cement

Types of Cement by Composition & Properties

Depending on the composition and properties there are various types of cement.

Ordinary Portland Cement (OPC):

Ordinary Portland cement is largely used in construction work. It is made of silicates of alumina (clay and shale) and calcium carbonate (limestone, chalk, and marl). It is used for general construction purposes mostly for concrete and masonry work.
It has great resistance to cracking and shrinkage however less resistance to chemical attack. Ordinary Portland cement is not ideal for the construction work which is exposed to sulfates in the soil.

Portland Pozzolana Cement (PPC):

Pozzolana cement is produced by mixing 30% of pozzolana with Ordinary Portland cement clinkers. It is also produced by adding pozzolana with the addition of gypsum or calcium sulfate or by thoroughly and evenly blending Portland cement and fine pozzolana.
This cement has a high resistance to different chemical attacks on concrete compared to ordinary Portland cement, and therefore, it is commonly used. It is used in hydraulic structures, such as bridges, piers, dams, marine structures, construction near the seashore, sewer works, and so on.

White Cement:

White cement is prepared from raw materials without Iron oxide and reduces manganese oxide. It resembles Portland cement except for its white color. It is more costly as compared to Portland cement so not economical for ordinary work.

It is used for architectural applications such as precast curtain walls, exterior and interior ornamental work such as facing slabs, flooring, and decorative concrete products.

Rapid Hardening cement:

Rapid hardening cement is quite similar to ordinary Portland cement. This cement has actually increased lime material and includes higher c3s material and by reducing the C2S content in the cement, finer grinding provides higher strength than ordinary Portland cement at an early stage.
The strength of Rapid Hardening cement of three days is nearly the same as the seven days strength of Ordinary Portland cement. It requires the same water-cement ratio as ordinary Portland cement. The benefit of this cement is that formwork can be removed earlier, which saves construction time and reduces the cost of construction by saving formwork cost.
This type of cement is not chosen for large construction projects. This type of cement is used where there is a requirement for high early strength like Pavements, busy roads, and prefabricated concrete construction.

Quick Setting Cement:

Quick setting cement is the cement that sets in a very short time. This type of cement is used where works is to be completed in a very short period. The initial setting time is 5 minutes and the final setting time is thirty minutes. Aluminum sulfate (1% to 3% by weight of clinker) enhances the hydration rate of silicate. It is used in underwater construction and also used in rainy and cold weather conditions.

Quick-Setting-Cement

Sulfate Resisting Cement:

It is manufactured by reduced the contents of C4AF and the percentage of C3A below 5%. Sulfate resisting cement is used to minimize the risk of sulfate attack on concrete (alkaline problems) and therefore is used in the construction of foundations and sewer treatment tanks where the soil has high sulfate content.
Sulfate resisting cement is used in construction exposed to serious sulfate act by water and soil in places like canals linings, culverts, retaining walls, etc.

High alumina Cement:

This type of cement has rich alumina content of about 35% and it should keep the proportion by weight of alumina to the lime in between 0.85 to 1.30. which helps in achieving maximum high strength within a short period. This type of cement is used where a structure goes through high temperatures like workshops, foundries, chemical plants, and furnaces.

Blast furnace slag cement:

This type of cement is less expensive than Ordinary Portland cement. it is manufactured by inter grinding of OPC clinker and blast furnace slag. A maximum of 65 percent of the blend could be comprised of blast furnace slag. Blast furnace slag cement develops reduced heat of hydration and has less early strength.

Blast-furnace-slag-cement

Colored Cement:

It is manufactured by adding 5 to 10 percent of appropriate coloring pigment to the ordinary Portland cement. Types of pigments are chosen according to the preferred color. it is mostly used to fill tile joints and also Colored cement is used for different decorative work.

Low heat Portland cement:

This type of cement is manufactured by reducing the C3S content and raising the C2S content. It has less compressive strength than ordinary Portland cement. It has less lime content than OPC. This type of cement is mostly used in the construction of retaining walls and it is strictly not suitable for thin concrete structures.

Expansive cement:

This type of cement is produced by including a stabilizer which stabilizes the cement to expand. This can be attained by adding 10 to 20% of sulphoaluminate and 15% of stabilizer to the ordinary Portland cement clinker. It is used for sealing joints and grouting anchor bolts.

Air Entraining Cement:

Air entraining cement is a special type of cement that entrains tinny air bubbles in concrete. This type of cement is manufactured by adding 0.025– 0.1% of air-entraining agents to the ordinary Portland cement clinker. Air entraining agents are generally made up of wood resins, calcium agents, veggie oils, and animal fats.
It is seen that entrainment of air applying cement increases resistance to frost action, fire, scaling, and other similar defects.

When the water in concrete obtains frizzed due to low temperature, it expands. When air-entraining cement is used, the air voids in concrete provide space for water to expand without cracking concrete. But this type of cement does not give high strength in concrete. It is used in areas where the temperature is very low.

Hydrophobic cement:

This type of cement is produced by grinding ordinary Portland cement clinker with water oleic acid or stearic acid. These chemicals develop a layer on the cement particle and do not allow water to mix and start the hydration process.

When cement and aggregate are thoroughly mixed in the mixer, protective layers break and start regular hydration with some air entrainment which increases workability. The formation around each grain of cement decreases the rate of deterioration of the cement during long storage, transport, or under unfavorable conditions.
Generally, it is used in the construction of water structures such as dams, spillways, or other submerged structures.

Water Resistant Portland cement:

This type of cement is produced by including small portions of metallic secretes in OPC during grinding. This type of cement is used in foundations, water tanks & various other water retaining structures.

Water Resistant Portland cement