Nowadays PPC is used as a replacement for OPC. So, the most confusing thing is how to make the correct choice. Here is one article please read to know about various advantages and disadvantages of OPC and PPC.OPC vs PPC: How to Make the Right Choice Hope you find it useful.
OPC cement - Its now a days generally blended with mineral admixtures like Flyash, GGBFS & Micro silica / silica fume etc. to enhance the properties of concrete.
Mineral admixture are finer than the OPC cement particles, so they greatly enhance the properties of concrete like workability, finishability, impermeability and lateral strength gain.
Now a days OPC is directly use in very less type of concrete and mortar mixes.
PPC - They are very good in all aspect and highly recommended for durability of product.
As the mineral admixture % blended with OPC by manufacturer are different in products manufactured by different companies of cement.
It is better to use only one brand of cement in case of use in RCC work, this enables the correct prediction of strength gain and other properties of concrete.
Best way of doing concrete, instead of using blended cement (PPC) for concrete, do blend on your own as per concrete design by you (Using OPC cement and Mineral admixture of your choice)
Always remember blended cement gives you a better quality of concrete, rather than using only OPC cement for RCC Works.
There are some folks who do not understand the chemistry of concrete, simply says for RCC use - OPC and for finishing use PPC (They are simply not a concrete designer or never did designing of concrete nor they know anything in it except what they seen in text books).
Benefits of concrete by blending cement.
Cost of concrete reduces to great extend.
Finishing of concrete increase to great extend.
Reduction in shrinkage cracks.
Reduction in porosity of concrete.
Increase in the concrete strength in later age.
Reduction in CO2 Emission, hence reduction in pollution.
Structures made with this are called green building.
Reduction in national property wastage.
Greatly enhance durability.
There are many more advantages of using it.
There is a myth which says if you use PPC or flyash or GGBFS, your strength gain will reduce and your progress will go down due to waiting time for de-shuttering.
There is no such disadvantage.
Big slap to those mythic person made by RMC's
All RMC produce concrete by blending cement (So when you say OPC for concrete, PPC for finishing, do think on it. You might be ending in buying the blended cement concrete from RMC, without knowing the fact for which you made a claim)
After Reading all this, i would suggest you (Its only suggestion, its up to you to remember or disregard)
Forget about the myth which are spread by some peoples.
Do learn more about the current technology trend and how industry is advancing by making text book wrong which are written way back.
I am not arrogant nor threatening anyone, i wrote which i know so far. Others may have other opinion on same and are free to write about it.
I produced a high grade concretes by blending cement with mineral admixtures and rarely used Pure OPC concrete (where producing by blending not possible at site where site batching is done and no equipment's to ensure correct blending)