OPC and PPC Cement Which is Better

In this exclusive civil engineering article, you will come to know the variations among ordinary portland cement and portland pozzolana cement.

The main differences are given below :-

1. The ISI mark in OPC is provided with black color whereas it is provided in red color in PPC.

2. The major ingredients of OPC are calcareous materials which contain limestone 60 to 70%; argillaceous materials which contain silica 17 to 25% and alumina 3 to 8%; oxides of iron which contain gypsum, magnesia, sulphur trioxide, potash/sod 0.5 to 13%. The above ingredients are blended in fixed ratios and burnt in clinks to produce clinkers and later on grinded to desired fineness to form OPC.

Whereas,

The major ingredients of PPC are OPC clinkers 75 to 77%; gypsum 3 to 5%; pozzolana 10 to 25% which contain fly ash, rice husk ash, volcanic tuffs, pumicites, clay & shale. All these ingredients are grinded to develop OPC.

3. According to bureau of Indian standard, grades of OPC are 33 grade, 43 grade and 53 grade whereas there is one grade for PPC. Its strength is similar to 33 grade of OPC once curing is completed.

4. IS code of OPC for 33 grade is 269; for 43 grade is 8112 and for 53 grade is 12269 whereas IS code of PPC is 1489 (part 1 & 2) 1991.

Also Read: A huge lists of Indian Standard Codes for concrete and cement

5. In 3 days OPC attains a compressive strength of 35 N/mm2; in 7 days 43.5 N/mm2; in 28 days 55 N/mm2 whereas in 3 days PPC attains a compressive strength of 29 N/mm2; in 7 days 39 N/mm2 and in 28 days 56.5 N/mm2. So, preliminary strength of OPC is greater than PPC but the strength of PPC in long periods is greater than OPC. So, OPC is best suited for retaining higher strength at preliminary stage.

6. The stability of concrete with OPC is less as compared to PPC whereas stability of concrete with PPC is greater than OPC. So, the structure constructed with PPC is long-lasting.

7. Workability of concrete means how smoothly it can flow on the surface. The concrete with OPC contains less workability whereas the concrete with PPC contains greater workability.

8. Permeability means the quality of any material to calculate the quantity of liquid or water to move through them. As OPC does not contain pozzolanic material, it is extremely permeable to water whereas the permeability is less in OPC. So, it is ideal for bridge peers or foundations where water-resistant structures are required.

9. Heat of hydration means the formation of heat with the reaction of water & cement. For OPC less time is required for competion of hydration process. So, it generates more heat as compared to PPC. When cement creates more heats in less time, it should not be utilized for mass concreting as it can produce cracks in structures. For PPC, more time is required for completion of hydration process and as a result less heat is generated throughout hydration process. So, PPC is ideal for less concreting.

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Video Source: Engineering Motive