3 Basic Categories of Concrete

 

Concrete is a composite material produced after mixing aggregates and cement with water. Concrete is the second-most commonly used construction material worldwide, next to water.

 

Concrete looks like stone but not. Stone is just one of its aggregates along with gravel, sand, brick chips, and many other quarry materials.

 

Cement accounts for around 10 to 15 per cent of concrete. It is manufactured through a closely controlled chemical combination of calcium, silicon, aluminum, iron and other ingredients. Common materials used to manufacture cement include limestone, shells, and chalk or marl combined with shale, clay, slate, blast furnace slag, silica sand, and iron ore.

 

Cement is precious, reason why it is very important that in making concrete mix, the exact ratio of cement over water is always achieved. Apart from cement wastage, exact cement and water consistency impacts on the hardness, rigidity, and strength of concrete. For this purpose, concrete manufacturers use appropriate concrete mixing machines.

 

Concrete mix vary. Based on the variations in concrete materials and purposes, concrete can be classified into the following 3 basic categories:

 

1) Lime Concrete uses lime as the binding material. Lime is usually mixed with surki and khoa or stones in the proportion 1:2:5 unless otherwise specified. The khoa or stones are soaked in water before mixing. Lime concrete is used mainly in foundation and terrace roofing.

 

Use of lime concrete is advantageous because it- a) is cheaper than cement concrete; b) is more workable than cement concrete; c) has lower heat of hydration making it suitable for mass concrete works; d) is more resistant to fire; and e) is more resistant to sulfate attack.

 

Lime concrete, however, has its disadvantages like- a) lower strength than cement concrete; b) not as durable as cement concrete; and c) susceptible to frost.

 

2) Cement Concrete is used in most engineering and construction works. It consists of cement, sand, brick chips, or stone chips of the required size. The usual proportion is 1:2:4 or 1:3:6. After mixing the required amounts of concrete materials, the mix is cured with water for 28 days for proper strength building.

 

Cement concrete is a versatile with a wide range of applications. It can be used in structural applications such as beams, columns, slabs, and foundations. It can also be used in non-structural applications such as paving, curbing, and landscaping as well as in popular choice for precast applications such as pipes, paving stones, and sewer systems.

 

The main advantages of cement concrete are its strength, durability, and fire resistance. It is also relatively low maintenance and can be easily repaired if damaged.

 

Cement, however, is a relatively heavy material and can be difficult to work with. It is susceptible to cracking and can be damaged by extreme weather conditions.

 

3) Reinforced Cement Concretes are steel reinforced for enhancing the tensile strength. It is sometimes pre-stressed under compression to eliminate or reduce tensile stresses. The resulting concrete is known as Pre- stressed Concrete.

 

The steel reinforcements used in reinforced cement concrete are rods, bars, wires, meshes, other steel materials. The concrete is cast around these steel reinforcements to form the desired shape of concrete cast.