A substance that sets and hardens independently and can bind other materials together is called cement. Cement used for the construction purpose is characterized as hydraulic or non-hydraulic cement. Use of the cement is for the production of mortar and concrete the bonding of natural or artificial aggregates to form the strong material that will be durable in the face of normal environmental effects. A combination of cement and aggregates is known as concrete.
Advantage of cement
- Cement is used for binding materials
- It is easy to handle and apply
- Cements are suitable to contact with potable water
Composition of cement
Cement has several features such as setting time, rate of strength development, overall strength, durability, and color. Main compounds that are presented in cement and which decides the quality of the cement are as follows:
- Tricalcium silicate
- Dicalcium silicate
- Tricalcium aluminate
- Terracalcium alumino ferrite
Manufacturer of cement
There are many cement factory are available in the country. The processes of manufacturing the cement are as follows:
Cement is made up of limestone and clay or shale. The raw materials are extracted from the quarry crushed to a very fine powder and then blend in the correct proportion. Cement plants are located at the central to the minerals required to make the cement, which saves the transport costs and also reduces the price of the cement.
Types of cement
The cement process has broadly classified under two main heads such as dry process and wet process. There are many types of cement by blending different proportions of gypsum, clinker, and other additives. Cement used for the construction is classified under two different categories based on the cement properties such as hydraulic and non-hydraulic. Cement factory manufactures both hydraulic cement and non-hydraulic cement.
Non- hydraulic cement cannot harden while in contact with the water. Non-hydraulic cement is used by materials such as non-hydraulic lime and gypsum plasters and oxy chloride that has liquid properties. After using non-hydraulic cement for construction, it must be kept dry to gain strength and hold the structure of the construction. Non-hydraulic cement if used in mortars then the mortars can be set for drying out and gain the strength very slowly.
Hydraulic cement can set and harden after being combined with the water. The chemical reaction after hardening hydraulic cement mixtures retains strength and stability even after adding water in it. The mixtures become essentially insoluble in water when hydraulic cement is mixed with the water. Hydraulic cement is made with limestone, clay materials, and gypsum which is burned together in a high-temperature process and also drives off carbon dioxide and chemically combines the primary ingredients into new compounds.
High alumina cement
High alumina cement is obtained by fusing a mixture in the suitable proportion of alumina and calcareous material and grinding the resulting product to a fine powder. Raw materials used for high alumina cement are limestone and bauxite. This type of cement is useful for flowing water and for some grouting operations.