Cement – An Introduction
Switch on your television, chances are that you would run into a cement advertisement. Same hold good for a magazine or a newspaper. Cement has come a long way from being the ugly grey powder sold in plastic bags. Today they have become a brand by themselves. More and more consumers are looking for information on the Internet about cements. We thought, what is a better way to end this weekend than do it with a small post on this topic? So here goes…..
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Cement is the adhesive which holds the construction material such as bricks and tiles. But more importantly it is the largest contributor to the modern miracle we refer to as concrete.
We would not be touching on too many details in this post. After all, as with all other topics, we are now in the “grazing the field” mode. The article hopes to create awareness on this subject of cements along with a few details on choosing the grade.
Types of Cement
(Portions of this article are taken from ACC India Limited via The Hindu)
Broadly speaking there are two categories of cement
- Ordinary Portland cement
- Blended/composite cement
This type of cement is prepared by grinding clinker along with gypsum. This is available in several grades such as 33, 43, and 53. This type of cement can be used for all normal work.
This brings us to the question: “What exactly does the grade of the cement signify?”
Answer:The grade symbolises that at 28 days the cement mortar cube has a compressive strength of at least 33, 43 and 53 Mpa – Mega Pascals – respectively.
So, the higher the grade, the more compressive strength your building would have.
In this type of cement, high-quality clinker is inter-ground with gypsum and a performance enhancing cementitious material such as slag or Pozzolana. It comprises Portland slag cement or Fly-ash-based Portland Pozzolana cement. It may be used in all general construction such as concreting, brick joining, plaster and special construction. It gives the concrete better long-term strength and durability.
At this juncture, I am not sure if the blended/composite cement is more expensive than Portland cement, but it is logical to assume the same.
Certain advantages of concrete made from blended/composite cements over ordinary Portland cements are:
Long-term strength and durability.
Lower repairs hence lower maintenance cost.
Reduces leaching (washed up lime that comes out and weakens the construction).
Prevents crack formation. Less heat is generated while it sets in.
Resists chemical attacks from aggressive elements in the ground, water and air.
Protects reinforcement rods from rusting.
Suffers less shrinkage.
Provides smoother finish.
Requires less water to prepare concrete. In comparison to other cements, you can use about 10 per cent less water.
We would have more on this topic in the coming days, so stay tuned and/or subscribe to our newsletter.
Have a great weekend!!
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