Cement – Ingredients and Properties

WHAT IS CEMENT?

Cement is one of the most significant structural material used in construction. Cement is a binding agent that sets and hardens to adhere to building materials like sand,bricks,stone etc. Cement is a fine powder made of limestone,clay, bauxite and iron.

Cement when mixed with aggregates and sand produces concrete and when mixed with sand produces mortar which is used for brickwork, plaster,flooring etc. Cement is the most unavoidable element which dominates the construction sector.

MUST READ : MANUFACTURING PROCESS OF CEMENT

INGREDIENTS OF CEMENT

Cement is manufactured from Lime, silica, alumina and iron oxide. Lime is obtained from limestone and oxides of silica, alumina and iron which is found in clay and shale.

a) Lime

Lime is the major and main constituent of cement and which accounts to about 60-65%. Lime is the main ingredient  for production of calcium silicates aluminates and responsible for the cementing properties and strength of cement. The proportion of lime content can alter the properties of cement. Less quantity of lime can reduce the strength of cement and higher lime content can make the cement unsound. Lime in correct proportions is responsible for the strength of cement.

b) Silica

SiO2 or silicon dioxide is called silica. Silica is responsible for the formation of dicalcium silicate and tricalcium silicate in reaction with lime . Right proportions of silica plays a major part in inducing cement strength.

c) Alumina

Alumina is responsible for lowering the clinkering temperature and controlling the setting time of cement. Alumina imparts quick setting properties in cement and any increase in proportions can weaken the cement.

e) Iron oxide

Iron oxide is responsible for colour of the cement and it acts as a flux in the cement manufacturing process . It acts as a flux in high temperatures and combines with calcium and alumina to form tricalcium alumino ferrite which is the main ingredient behind the hardness of cement.

f) Magnesium oxide

Magnesium oxide is found in minor traces but increase in the quantity can reduce the strength of cement.

g) Sulphur Trioxide

Sulphur trioxide is available in traces but any increase can effect the cement quality.

PROPERTIES OF CEMENT

Cement is the most significant structural material used in construction.Cement is the most recognised binding material and can be used in any nature of structures starting from a home to sky scrappers, industrial structures ,bridges, roads etc. Cement when mixed with sand and aggregates forms concrete and when mixed with sand makes mortar.The serviceability, strength and durability of a structure is purely depend on the quality of cement which is being used for concrete and mortar.The properties of cement is directly related to the proportioning of ingredients, grinding, packing etc.