For housing construction, which is the best cement to be used?
The most commonly used cement for housing construction are as below mentioned,
1. Ordinary Portland Cement (OPC)
2. Portland Pozzalano Cement (PPC)
Ordinary Portland cement (OPC):-
It is the most famous and popular cement and widely used for the construction of buildings, even in every construction of work. It was Joseph Aspdin in 1824, who named it Portland cement; it was the same as Portland stone is in color and high quality.
Usage of OPC
1) It is also used for prestressed concrete.
2) All type of RCC structures, paver block, concrete blocks, OPC is recommended.
3) Suitable for all residential buildings, runways, highways, bridges, high-rise buildings, commercials, etc.
4) Also, it is the basic and main component in mortar, plaster, and non-specialty grout.
Benefits and advantages are likely to be mentioned below,
1) Grade availability are Grade 33, Grade 43, Grade 53,
2) In less time, It attains its strength,
3) Speedy construction due to the high early strength,
4) Highly resistant to sulphate attack due to less availability of Tricalcium aluminate (C3A),
5) Protection against alkali-aggregate reaction is very good due to the presence of low alkali content,
Demerits and disadvantages are likely to be mentioned below,
1. It is not for large scale of construction due to higher in heat of hydration than Portland Pozzalano Cement (PPC)
2) PPC is cheaper than OPC
3) Permeability is very high due to finer, and consequently lower in durability,
4) PPC is more durable than OPC,
5) PPC is more solid concrete than OPC, due to this reason, pumping over OPC is a bit difficult.
Grade 33 and Grade 43 OPC are now not available in the market due to the old grade of cement, and in the present scenario, Grade 53 OPC has replaced both of them.
OPC is manufactured by two methods,
1) Wet Manufacturing process,
2) Dry Manufacturing process.
There are three distinct stages of cement for manufacturing as follows,
1) Raw material acquisition
2) Clinker production,
3) Cement Grinding, packing, and distribution of cement.
Chemical Composition in OPC
1) Lime
Deficiency causes a decrease in strength.
2) Silica
Adds the strength, by undergoing a chemical reaction with calcium to form di-calcium and tri-calcium silicates.
3) Alumina
Presence in excessive accelerates the cement setting but weakens the cement,
4) Iron Oxide
Iron oxide in higher volume leads the cement to fuse in a difficult position and form clinkers.
5) Magnesia
Shall not exceed 5% by mass.
6) Sulphur Trioxide
Due to excessive volume, makes cement is unsound.
7) Alkalies
Larger in quantity leads to efflorescence.
8) Gypsum
Setting time is increased by adding gypsum to the cement and a small amount is added.
Application of OPC
Type I: For universally useful.
Type IA: It is comparable to Type I, however when air entrainment is wanted.
Type II: For moderate sulfate obstruction.
Type IIA: It is the same as Type II, yet when the air passage is wanted.
Type II (MH): It is similar to Type II, yet when moderate fieriness of hydration is wanted.
Type II (MH) A: Similar to Type II (MH), however when air entrainment is wanted.
Type III: For high beginning power.
Type IIIA: Alike to Type III, yet when air entrainment is wanted.
Type IV: For low fieriness of hydration.
Type V: for high sulfate opposition
In conclusion
OPC is a product derived from unprocessed common natural materials like clay and limestone, so it is a complex product. For the cement industry, it is necessary for them to produce the clinker that would facilitate the production of low water-cement concrete that is more durable than general strength concrete.
To be continued…
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