What are the different types of cement?
Generally, there are two different types of cement available in the market, they are OPC & PPC.
OPC cement is also known as “Ordinary Portland Cement”. OPC cement comes in 3 grades, they are 33, 43, & 53 grade cement. But why it is known as Portland Cement?
It is just because this cement was invented in “Portland” which is in England. It was invented by Sir Joseph Aspdin in 1824. When they prepared the concrete by using this cement, it was just the replica of the stone which was used on a large scale for construction in those days. This concrete was so similar to that stone, so from then this cement is known as “Ordinary Portland Cement”.
If we talk about cement before 1987 as per Indian Standards there was only one type of cement available. But after 1987 this OPC cement was differentiated in three grades. They are OPC 33, OPC 43 & OPC 53. Now we will look at what do these grades represent.
These grades are known for the strength which is going to be achieved on the 28th day. If the cement produces 33N/mm2 strength after 28 days then it is known as OPC 33 grade cement. If the cement produces 43N/mm2 strength after 28 days then it is known as OPC 43 grade cement. If the cement produces 53N/mm2 strength after 28 days then it is known as OPC 53 grade cement.
Is it important to prefer brands while buying the cement?
As we know that the main ingredient of the cement is limestone. If we are going for a brand then it is better because we will get the far better quality of cement as they are using good quality of limestone while manufacturing the cement.
There are also other reasons like their quality control is good, they have advanced level of instruments which helps in grinding the required material finer and also they provide very good packing. So due to this, we get a very good quality of cement.
Which grade of OPC cement we can select?
It depends on the required strength we need to produce. Lower grade cement is economical as compared to the higher ones. But if we use higher grade cement then the cement consumption reduces. So it does not make much difference as per the cost is concerned.
What is the difference between OPC and PPC Cement?
Initially in the whole world OPC cement was being used on a large scale. But then the whole world switched to PPC cement. Till 1997 in full world only 40% of the world was using OPC type cement. At that time in INDIA 70%, OPC cement was used. But then the Indian government brought many rules and regulations in action and from then PPC cement is being used on a large scale. This was done because there is a technical reason also and environmental reason also. If we have a look at the composition of the cement.
We can see that Lime (CaO) 60 to 67%, Silica (SiO2) 17 to 25%, Alumina (Al2O3) 3 to 8%, Iron Oxide (Fe2O3) 0.5 to 6%, Magnesia (MgO) 0.1 to 4%, Sulphur Trioxide (SO3) 1 to 3%, Soda and Potash (Na2O + K2O) 0.5 to 1.3%. So in this, you can see that in the composition of cement the content of lime is maximum if we compare it with others.
When lime is mixed with water at that time reaction takes place and due to this reaction, Carbon-dioxide is released. This carbon-dioxide is very harmful to our environment and during this reaction, it is released in more amount as lime content is maximum in cement.
So due to this, the whole world understood the consequences of OPC cement and they reduced the use of OPC cement and promoted PPC cement.
PPC Cement is known as Pozzolanic Portland Cement. In the composition of cement content of lime is reduced and pozzolanic materials are added in it like silica fumes, fly ash, volcanic ash, rice husk.
These pozzolanic materials are added in the cement which helps in filling very fine pores present in the concrete so that it produces very dense material and we get very good strength of concrete. If you are using PPC cement for mass concreting like foundation, dam or plastering then you will get very good results.
Its durability is also very high. It’s setting time is more as compared to OPC cement because the lime content is low in PPC cement. But if we compare both of them for long term then PPC cement achieves more strength then OPC cement. Crack formation in PPC based concrete is also very low as heat released is also low.
If you are constructing in the hot areas then you must use PPC based concrete. Its cost is also less then OPC cement so it is economical over OPC cement. PPC cement is eco-friendly as it doesn’t harm our environment as much as OPC cement.
So using PPC cement is more beneficial then using OPC cement.