DIFFERENT GRADES OF PORTLAND CEMENT AND ITS USES

Grade of Cement

A cement is a binder a substance used for construction that sets,hardens and adheres to other materials to bind them together.Cement generally refers to a very fine powdery substance made up of limestone,clay.bauxite & iron ore and may include shells,chalk,marl,blast furnace slag,slate etc.The raw ingredients are processed in cement manufacturing plants and heated to form a rock hard substance,which then grounded into a fine powder.Cement mixed with water causes a chemical reaction and forms a paste that sets and hardens to bind structures of building materials.

Now a days cement is an integral part of the urban infrastructure.Cement was first discovered in 1824 by Joseph Aspadin in England.Due to the similarity in colour and quality when harden like Portland stone Aspadin called it  Portland cement.Aspadin cement was nothing like modern Portland cement but was the first step in its development.Now there are 3 different Grade of Ordinary Portland Cement available in market.

The Grade of cement indicate the strength of cement.Strength is generally measured as compressive strength.

 Three Grade of OPC are;

• Grade - 33
• Grade - 43
• Grade - 53

GRADE -33

Grade 33 Portland cement refers that cement has a compressive strength of 33 N/mm^2 at the end of 28 days of curing. This grade has high workability as compare to the other grade.In motor for plaster and for masonry, the grade 33 was commonly used.

Fineness = 300 kg/m^2

Compressive strength after   3 days = 16 N/mm^2

Compressive strength after   7 days = 22 N/mm^2

Compressive strength after 28 days = 33 N/mm^2

 Grade 33 - Should always cover the specification (IS CODE 269).

GRADE - 43

Grade 43 Portland cement refers that cement has a compressive strength of 43 N/mm^2 at the end of 28 days of curing.Grade 43 Portland cement was generally used in reinforced cement concrete construction which also called as RCC.

Grade 43 cement is mainly used in;

• Ready mix concrete
• RCC works
• Pre-cast concrete
• Silos and chimneys

Fineness = 225 kg/m^2

Compressive strength after  3 days = 23 N/mm^2

Compressive strength after  7 days = 33 N/mm^2

Compressive strength after 28days = 43 N/mm^2

The Grade 43 - Should always cover the specification (IS CODE 8112).

GRADE - 53 

Grade 53 Portland cement refers that cement has a compressive strength of 53 N/mm^2 at the end of 28 days of curing.In grade 53 Portland cement chloride content is low and cement has a good ability to resist sulphate.The quantity of the cement is required less in volume because this grade has high strength as we compare to other Portland cement grade.

Grade 53 cement is mainly used in;

• RCC Bridges
• Pre-cast concrete
• Construction of industrial buildings
• Construction of roads and subways
• Concrete sleepers for railways

Fineness = 225 kg/m^2

Compressive strength after  3 days = 27 N/mm^2

Compressive strength after  7 days = 37 N/mm^2

Compressive strength after 28days = 53 N/mm^2

The Grade 53 - Should always cover the specification (IS CODE 12269).