Why is Cement Important Construction Material?
Till date cement has been a very important building materials used in the construction industry.
Because of its both adhesive and cohesive properties cement can make bonding and bind particles of solid matter into a compact durable solid mass.
The definition of cement is anything that binds, particularly a substance made of burned lime, clay, sand and water to make mortar or sand, water and gravel to make concrete.
History of Cement:
It was 191 years ago that cement was developed
Joseph Aspdin of England first patented the manufacture of a very improvised type of cementitious material for building construction in 1824
The hardened cement paste resembled the natural stone occurring at Portland in England. Hence it was named as Portland cement
Cement has replaced all other binding materials, for example, clay and lime, which ruled high for hundreds years, in construction from last century
The reason why cement has become famous is that, cement is the strongest binding material amongst, lime and cement
Cement is now used in many construction trade items like plain concrete, reinforced concrete, mortar, plaster, grouts, paints and precast elements
In an ordinary building construction the cement accounts to about 10 to 12% of the cost of construction. In some other major constructions like bridges it’s very much more
Some of the reasons for its popularity and universal acceptance are listed below:
Cement can be produced in large volumes in controlled condition, packed and transported over long distances
Cement is several times stronger binding material than lime and clay
It can be mixed and used at will with locally available materials at site
When stored properly in ordinary atmosphere, it does not deteriorate or react for reasonably longer time
When mixed with water, starts setting very early and acquires sufficient strength in a day or two, where as other binding materials require much longer time
When water is added to quick lime, lot of head is generated, but in case of cement, heat generated is unnoticeable and much lesser
It can withstand compressive stresses well. Where tension and shear stresses occur it gives good bond to steel reinforcement and transfers excess stresses to steel
It is produced from the materials like limestone, hematite, bauxite, clay etc which are abundantly available in upper crust of the earth
The various types of Cement are-
Ordinary Portland Cement(OPC)
Portland Pozzolana Cement(PPC)
Rapid Hardening Portland Cement
Extra Rapid Hardening Cement
Portland Slag Cement
Hydrophobic Portland Cement
Low Heat Portland Cement
Sulphate Resisting Portland Cement
Quick Setting Cement
High Alumina Cement
Super Sulphated Cement
Masonry Cement
Oil Well Cement
White Portland Cement
Colored Cement
Water-Proof Cement
Expansive Cement
Sand Cement, and
Air-Entraining Portland Cement
Cement Grades:
There are Three Main Grades of Cement
33 Grade Ordinary Portland Cement:
33 grade cement refers to cement that has a compressive strength of 33 N/mm2 at the end of 28 days of curing. This type of cement is used for general construction work under normal environmental condition.
43 Grade Ordinary Portland Cement:
43 grade cement refers to cement that has a comprehensive strength of 43 N/mm2 at the end of 28 days of curing. This type of cement is used for plain concrete work and plastering works.
53 Grade Ordinary Portland Cement:
53 grade cement refers to cement that has a compressive strength of 53 N/mm2 at the end of 28 days of curing. Unlike other grades of cement, 53 grade ordinary portland cement is used for structural purposes as in reinforced cement concrete.
Every grade of cement is suitable for different set of tasks as each of them have varying levels of strength. Using the wrong strength levels for a particular job can affect your overall structural design. In the world of construction, most professionals opt for 53 grade cement.
