Portland Pozzolana Cement (PPC) PPC is a type of blended cement. It consists of 15-35% pozzolanic material, 4% gypsum and the rest is clinker. PPC as per BIS code is equivalent to that of 33 grade. Since the pozzolanic material reacts with calcium hydroxide liberated by the hydrating Portland cement and forms cementatious compounds, PPC makes the concrete more impermeable and denser.
What does PPC cement mean?
Portland Pozzolana Cement (PPC)
What is PPC and OPC?
Difference Between OPC and PPC Cement Sheikh Anwarul Mahdi PPC cement full form is Portland Pozzolana Cement, OPC cement full form is Ordinary Portland Cement, Both PPC and OPC cement is used in construction. PPC cement is a variant of OPC cement. These two types of cement differ from each other in terms of component, strength, heat generation, the percentage of several components, durability, grades, cost, eco-friendly nature, application, setting time, curing period, etc.
Sources | OPC Cement | PPC Cement | |
---|---|---|---|
1 | Definition/ Components | A mixture of limestone and other raw materials like argillaceous, calcareous, and gypsum is prepared and then grinded to prepare OPC (Ordinary Portland Cement). | PPC (Portland Pozzolana Cement) is prepared by adding Pozzolanic materials to OPC. So, the main components are OPC, gypsum, and pozzolanic materials (15~35%) which include calcined clay, volcanic ash, fly ash, or silica fumes. |
2 | Strength | Initial strength is higher than PPC. | PPC concrete has higher strength than OPC concrete over a longer period of time. |
3 | Heat of hydration | Generates more heat than PPC in hydration reaction which makes it less suitable for mass casting. | It has a slow hydration process and thus generates less heat than OPC. |
4 | Durability | OPC concrete is less durable in aggressive weather. | PPC concrete is more durable in aggressive weather. |
5 | Cost | Costlier than PPC. | Cheaper than OPC. |
6 | Environmental Impact | Emits CO 2 during the manufacturing process. | It constitutes industrial and natural waste which makes it eco-friendly. |
7 | Application/ | It is suitable where fast construction is required but not suitable for mass concreting due to heat issues as mentioned above. | It is suitable for all types of construction work. For example RCC casting of buildings, mass concreting for bridges, and even plastering and other non-structural works. |
8 | Setting Time | Lower than PPC. Its initial setting time is 30 minutes and the final setting time is 280 minutes. Its faster setting time helps faster construction. | The setting time of PPC portland is higher than OPC. Its initial setting time is 30 minutes and the final setting time is 600 minutes. Its slower setting time helps to get better finishing. |
9 | OPC has finiteness of 225 sq.m/kg. It has lower fineness than PPC. So, it has higher permeability resulting in lower durability. | OPC has finiteness of 300 sq.m/kg. It has higher fineness than OPC. So, it has lower permeability resulting in higher durability. | |
10 | Grades available | 33 Grade, 43 Grade, and 53 Grade OPC cement are available. | No specified grade of PPC cement is available. |
11 | Lower than PPC. | Higher than OPC. | |
12 | Resistance against chemical attack | It has lower resistance against alkalis, sulfates, chlorides, etc. | It has higher resistance against alkalis, sulfates, chlorides, etc. |
Difference Between OPC and PPC Cement
Is PPC better than OPC?
PPC has an edge on OPC as PPC has slower rate of heat of hydration. Thereby PPC is prone to less cracks & reduced shrinkage), better workability and finishing (as fly ash based cement are spherical in shape and finer in size).
Can we use PPC for RCC?
Use of Fly Ash Blended Cements in Cement Concrete (PPCC) in RCC Structures 3.1 Subject to General Guidelines detailed out as above, PPC manufactured conforming to IS:1489 (Part-I) shall be treated at par with OPC for manufacture of Design Mix Concrete for structural use in RCC.
Which is the best cement for RCC?
1. Which Type of Cement to Opt? – There are various categories of cement used in building works for various purposes. Thus, it is important to understand properties of each type of cement and their uses. There are commonly three types of cement used in general construction purposes i.e.
Which is cheaper OPC or PPC?
Difference Between OPC and PPC Cement – The main differences in their characteristics and uses are –
Portland Pozzolana Cement is a variation of Ordinary Portland Cement. Pozzolana materials namely fly ash, volcanic ash, are added to the OPC so that it becomes PPC. Pozzolana materials are added to the cement in the ratio of 15% to 35% by weight.Both are ecofriendly materials but Pozzolana Cement uses natural and industrial waste thus reducing the environmental pollution.
OPC | PPC |
---|---|
It has higher strength than PPC in the initial stage. | The strength of PPC is good than OPC in long terms. |
It has high heat of hydration making it unfavorable for mass concreting. | The hydration process is slower than OPC resulting low heat of hydration. Therefore, it is suitable for mass concreting. |
The presence of sulphates, alkalies, chlorides, etc. is higher and less resistant than PPC. | It has low percentage of sulphate alkalis, chlorides, magnesia and free lime in its composition, which makes the concrete durable. |
OPC is not favorable in aggressive weather. | Show greater resistance to aggressive weather. |
OPC cement are available in three grades, such as 33 Grade, 43 Grade, 53 Grade | PPC is available in any specific grades. |
It is slightly costlier than PPC. | Cheaper than OPC. |
Conclusion: Both OPC and PPC are commonly used cements in construction. These days, PPC is used as a substitute of OPC. PPC is a variation of OPC which adds a mixture of a pozzolanic material that helps to enhance the strength of the concrete. PPC also brings down the amount of OPC requirement in making concrete.
Which cement is best for Wall?
OPC 43 is the best cement for plastering both exterior and interior walls of low residential buildings and OPC 53 is best for plastering high rise buildings. OPC is available in 3 grades in the market, OPC 33, OPC 43, and OPC 53.
Why is OPC 53 grade cement?
53 Grade Ordinary Portland Cement (OPC 53) – This grade was introduced in the country by BIS in the year 1987 and commercial production started from 1991. Advent of this grade in the country owes it to the improved technology adopted by modern cement plants. OPC 53 Grade cement is required to conform to BIS specification IS:12269-1987 with a designed strength for 28 days being a minimum of 53 MPa or 530 kg/sqcm.53 Grade OPC provides high strength and durability to structures because of its optimum particle size distribution and superior crystallized structure.
- Being a high strength cement, it provides numerous advantages wherever concrete for special high strength application is required, such as in the construction of skyscrapers, bridges, flyovers, chimneys, runways, concrete roads and other heavy load bearing structures.
- Not only is this grade of cement stronger than other grades / types, it is also more durable.
Further, by substituting lower grade cement with OPC 53, overall savings can be obtained through reduced quantity of cement that would be required to be used. A savings of 8-10% can be achieved with the use of 53 Grade OPC in place of any other grade.53 Grade cement attains higher early strength as compared to any other grade of cement but because of early gain, does not increase much after 28 days.
- In addition, due to faster hydration process, the cement releases heat of hydration at a much faster rate initially and therefore, the chances of micro cracking of concrete is much greater.
- Thus, during initial setting period of concrete, the higher heat of hydration can lead to damage arising out of micro cracks with in the concrete structure, which may not be visible on the surface.
The situation can be worsened when construction supervisors / masons tend to increase the quantity of cement in concrete with a wrong notion that such increases are better for both strength and durability of concrete. Grade 53 should therefore be used only where such application is warranted for making the concrete of higher strength, where good supervision and quality assurance measures are in place and where proper precautions are taken to relieve the higher heat of hydration through a proper curing process.
Which is better PCC or RCC?
In terms of strength, naturally, RCC is stronger because the reinforcement helps in load-carrying capacity. PCC is weaker and is only used for layering surfaces like plastering work or flooring and most importantly in the layering if excavation to cast footings.
What is the difference between PPC cement and PPC cement?
Difference Between OPC and PPC Cement – The main differences in their characteristics and uses are –
Portland Pozzolana Cement is a variation of Ordinary Portland Cement. Pozzolana materials namely fly ash, volcanic ash, are added to the OPC so that it becomes PPC. Pozzolana materials are added to the cement in the ratio of 15% to 35% by weight.Both are ecofriendly materials but Pozzolana Cement uses natural and industrial waste thus reducing the environmental pollution.
OPC | PPC |
---|---|
It has higher strength than PPC in the initial stage. | The strength of PPC is good than OPC in long terms. |
It has high heat of hydration making it unfavorable for mass concreting. | The hydration process is slower than OPC resulting low heat of hydration. Therefore, it is suitable for mass concreting. |
The presence of sulphates, alkalies, chlorides, etc. is higher and less resistant than PPC. | It has low percentage of sulphate alkalis, chlorides, magnesia and free lime in its composition, which makes the concrete durable. |
OPC is not favorable in aggressive weather. | Show greater resistance to aggressive weather. |
OPC cement are available in three grades, such as 33 Grade, 43 Grade, 53 Grade | PPC is available in any specific grades. |
It is slightly costlier than PPC. | Cheaper than OPC. |
Conclusion: Both OPC and PPC are commonly used cements in construction. These days, PPC is used as a substitute of OPC. PPC is a variation of OPC which adds a mixture of a pozzolanic material that helps to enhance the strength of the concrete. PPC also brings down the amount of OPC requirement in making concrete.
Which is better PPC or composite cement?
Composite Cements – S.P. Deolalkar, in Designing Green Cement Plants, 2016 2.1 Composite Cements Blended cements with more than one blending material are called composite cements. For instance: Clinker + fly ash + blast furnace slag Clinker + fly ash + limestone powder Clinker + blast furnace slag + limestone 2.2 Slag and fly ash complement each other in a composite cement.
- Composite cement made with 60% OPC + 30% fly ash + 5% limestone powder has higher strength than PPC made with 30% fly ash.2.3 Production of multi-component cements enables not only fuel energy savings (by 30-40%) but also increased volumes of concrete production.
- Composite cements with fly ash additive can be used to produce concretes for special application.
They are suitable for producing alkaline and sulfate corrosion-resistant concrete. Use of fly ash-slag mix allows optimization of the main characteristics of cement clinker and reduction of CO 2 emissions due to a greater cement/clinker ratio.2.4 In the future, emitting CO 2 may attract penalties.
- Therefore clinker will be increasingly replaced by materials like fly ash, slag, limestone powder, natural pozzolanas, etc.2.5 The type of additive used for making composite cement will depend on its availability locally.
- From this point of view, limestone powder suggests itself as the most convenient additive for use in cement plants.2.6 The European Cement Standard EN 197-1 1 uses Portland Composite Cement as a generic term for the entire Group of CEM II cements.
They include CEM II-S Portland slag cements. This category includes: Portland—silica flume cement Portland—pozzolana cement Portland—fly ash cement Portland—burnt shale cement Portland—limestone cement It is also used for CEM II M cements. They are cements containing Portland cement clinker plus other constituents like slag and silica flume that can be combined with one another.
These cements, in addition to the prospects for CO 2 reduction and conservation of resources, also offer considerable opportunities for optimizing properties like workability, strength development, and durability.2.6.1 Portland composite cements CEM-II M made with granulated slag and limestone have been primarily used so far for industrial purposes.
Similar results can be expected from CEM-II S cements made from fly ash and limestone complying with EN 450 as main cement constituents.2.7 Making of composite cements Plants that are already making blended cements can easily and conveniently make composite cements. Figure 2.2.1, Flow chart for making composite cement with fly ash, clinker, limestone, and gypsum.2.10 Of necessity in a cement plant that simultaneously produces different types of cements arrangements would have to be made to store them separately.
Configuration of mills making these cements and corresponding silos for storage would have to be worked out carefully, taking into account the volume and consistency of demand for each type of cement produced.2.10.1 For small and infrequent demands a multi-compartment silo could be used to store different types of cement.
Again, factors like: dispatches by road and or rail and their respective volumes dispatches bagged or in bulk would have to be taken into account in planning the overall layout of cement grinding, storage, and dispatch sections. Thus a layout would have to be worked out specifically for each plant to meet its requirements as well as possible.
Which grade PPC cement is best?
Stay updated on cement standards Jagvir Goyal Cement and steel being the two most important materials that govern the strength of a structure, remain under constant gaze of Bureau of Indian Standards. BIS keeps reviewing the specifications and parameters regarding these from time to time and revises the codal instructions for their properties and usage.
Draft instructions are circulated among all prominent engineers for their opinion before adopting the changes and revising the codes. Recently, cement codes have undergone significant changes and it is important for a house builder to be in know of these. Types of cement: There are 13 types of cement for which BIS has issued specifications and IS code numbers.
Many of these cements are use specific. These include Rapid hardening cement, Portland slag cement, low heat Portland cement, Ordinary Portland Cement, Portland Pozzolana cement, High Alumina Cement, White Portland Cement and many others. Of these, only three types of cement are used by a house builder for his house.
- These are Ordinary Portland Cement, Portland Pozzolana Cement and White Portland cement.
- IS Codes: The Ordinary Portland Cement when used by the house builders should conform to IS 269.
- The Portland Pozzolana Cement carries IS 1489 Part I mark.
- The White Portland Cement carries IS 8042 mark.
- Ordinary Portland Cement is commonly known as OPC and Portland Pozzolana cement is commonly known as PPC.
White Portland Cement is commonly known as White cement. While the OPC and PPC are supplied in 50 kg bags, white cement is used only for some specific purposes in the house and thus its consumption in a house is very small. It is therefore purchased in 1 kg packs.
Grades: Earlier there used to be three grades of OPC. Now, as per latest revision of IS Code, there are five grades of OPC. These are 33 grade, 43 grade, 53 grade, 43 S grade and 53 S grade. There are no grades in PPC or in any other type of cement.43 S grade and 53 S grade of cement are used in Railway Engineering for manufacture of sleepers.
Here, S stands for Sleepers. OPC 33 grade, 43 grade and 53 grade cements are used for General purpose engineering such as building construction. The43 grade OPC is stronger than 33 grade cement and 53 grade cement is still stronger than 43 grade cement.
Naturally, the tendency of the house builder is to opt for 53 grade cement to have a stronger structure. Codes for cement grades: Earlier, there used to be three IS codes for different grades of OPC. For OPC 33 grade, the IS code was IS 269 and cement bags were marked with IS 269 mark. For 43 grade OPC, the IS code was IS 8112.
The cement bags carrying IS 8112 mark were presumed to be having 43 grade cement. For 53 grade cement, IS code used to be IS 12269. All cement bags having 53 grade cement carried IS 12269 mark. In 2015, IS code for OPC has been revised and all grades of cement have been included in one IS code only.
Now, all cement bags containing OPC are supposed to carry IS 269 mark only irrespective of grade of cement contained in it. Further, each bag will further mention whether it carries 33 grade cement or 43 grade cement or 53 grade cement. So don’t look for IS 8112 mark or IS 12269 mark any more while buying cement.
Rather, look for IS 269 mark only and further, the grade of cement as mentioned on the bag. Why the grades: In all grades of Ordinary Portland Cement, same raw material is used. The difference between different grades of cement is due to the difference in proportion of raw materials in cement.
- Variation in proportion of raw materials in cement alters its physical properties and produces stronger varieties of cement, classified as 43 grade and 53 grade cement.
- Types of PPC: There are two types of Portland Pozzolana cement or PPC.
- One type of cement contains fly ash as the pozzolana material.
The other type of PPC contains calcined clay as pozzolana material. PPC containing fly ash has been given IS 1489 (Part 1) mark. PPC containing calcined clay has been given IS 1489 (Part II) mark. Use of different types of pozzolana materials alters physical and chemical properties of cement.
In building work, fly ash based PPC is used. Thus, while choosing PPC for one’s house, one should look for IS 1489 (Part 1) mark on the cement bags. Strength values of OPC & PPC: As explained above, of the three grades of OPC, 53 grade is the strongest. Its strength is 530 kg per sq. cm. OPC 43 grade cement comes next.
It has a strength of 430 kg per sq cm. OPC 33 grade has 330 kg per sq cm of strength. PPC is considered to have strength equivalent to that of OPC 33 grade cement. Therefore, its strength is 330 kg per sq cm. These are the minimum strength requirements for each grade and type of cement to win ISI mark.
- To be on safer side, the cement produced by cement manufacturers has much more strength than these minimum strength values.
- The buyer is therefore benefited on this account and gets better quality cement.
- Choice: From the above details, it becomes clear that some grades of Ordinary Portland Cement carry better strength than PPC.
Based on better strength, obvious choice of house builder shall, therefore, be 43 grade OPC or 53 grade OPC. Before finalising his choice, a house builder shall like to have a look at the difference in cost, presuming that 43 grade and 53 grade cement shall be much costlier than 33 grade cement or PPC.
- In actual, it is not so.
- There is not much difference in cost of different grades of cement.
- Thus a house builder shall like to easily finalise his choice as 43 grade cement or 53 grade cement.
- Actual scene: Though a house builder will like to choose 43 grade or 53 grade cement for his house but actual picture is that these grades of cement are simply no more available in the market.
Not only these, even 33 grade OPC is also not available in the market. Only PPC is available in the market and one is forced to choose it. Some dealers promise the house builders to provide OPC 43 grade or 53 grade cement to them by making a special request to the manufacturer to arrange cement of these grades for them but manufacturers agree to their request only if a large lot of OPC is demanded.
Availability of dry fly-ash from the thermal plants has attracted the cement manufacturers to produce more quantity of Portland Pozzolana Cement (PPC) and minimize the production Ordinary Portland Cement (OPC) as the manufacturing cost of PPC proves much lesser than that of OPC to them. This occurs because a substantial component of OPC clinker gets replaced with fly ash in PPC.
The percentage rests somewhere between 15 to 35 per cent. Fly ash is freely available to the manufacturers from thermal plants. Though production cost is less, the market rate of both types of cement i.e. OPC and PPC is almost the same. Important ingredient Every house builder wants to choose the best type and brand of cement for construction of his house.
- Now, people have become aware of the grades of cement also.
- Many of the queries received are about the grade, type and brand of cement.
- A house builder wants to decide the best brand and grade and type of cement, fix up his dealer for supply of its lots as and when asked by him and free himself for other jobs related to the construction of his house.
The decision, therefore, needs to be taken after thorough consideration. Freshness of cement : The cement lot chosen should be as fresh as possible. The cement bags carry the week and year of manufacture marked on them. A house builder should try to buy a freshly arrived lot with dealer.
- Effort should be made to buy cement bags that are not more than two months old.
- Cement absorbs moisture from air and loses strength with time.
- In the latest IS code, Bureau of Indian standards has now made another provision that each bag of cement shall now carry the ‘Best before Date’ instruction.
- Earlier, no such instructions were given on cement bags.
Now, a buyer can check the date of manufacture and ‘best before date’ instruction on the cement bags and buy the lot of cement accordingly. The terms of choice Keeping in view the latest revision in IS code by BIS and other details as explained in the article, one may go ahead to finalise his choice of cement as under:
Look for OPC 43 grade cement or 53 grade cement, if available. If available, look for IS 269 mark on the bags along with grade of cement clearly mentioned on it. If OPC 43 grade or 53 Grade cement is not available, go ahead for buying PPC cement. In that case, look for IS 1489 Part I mark on the bags. Check the condition of cement bags. These must not be torn anywhere. The bags can be in jute or HDPE/PP or jute synthetic or multi-wall paper bags. Check the weight of Cement bags. See that net quantity of cement is 50 kg per bag, excluding the weight of bag. Most importantly, check the freshness of cement. Check the date of manufacture and newly introduced feature — ‘Best before date’— on the bags.
The writer is Engineer-in-Chief, Civil Engineering Dept in a Punjab PSU : Stay updated on cement standards
Is PPC cement good for concrete?
Best cement: OPC or PPC? – Both Ordinary Portland and Portland Pozzolana types of cement are widely used for construction purposes. OPC is produced by simply grinding limestone and secondary materials to a powder; and the Portland Pozzolana is a variation of ordinary Portland with an added mixture of Pozzuolanic materials like Fly ash, volcanic ash, clay, slag etc in the ratio of 15% to 35% by weight, which increases the strength of the concrete.
- Both OPC and PPC are eco-friendly materials but Pozzolana Cement is made of natural and industrial waste.
- OPC is available in 3 grades as grades 33, 43 and 53 and Pozzolana is available in only one grade and its strength is equal to the strength of grade 33 of OPC PPC produces highly durable concrete as it has low water permeability compared to OPC.
PPC has low initial setting strength compared to OPC but hardens over a period of time with proper curing. And PPC is cheaper also compared to OPC. PPC is highly resistant to sulphate attacks and thus it has its applications in mass concrete work like dams, huge foundations, and buildings near seashores, reservoirs and in other marine works.