Cement is basically classified in 3 categories PPC OPC43 OPC53 as per their quality.
So here we discuss specifically about each type of cement.
OPC 53 Grade Cement:
OPC (Ordinary Portland Cement) is the basic form of cement with 95% cement clinkers and 5% being gypsum.
Gypsum is as an additive to increase the setting time of the cement to a workable 30 minutes or more.
OPC Cement gives high compressive strength at early ages and at 28 days. A 53 Grade cement gives up to 70 MPa strength against a minimum 53 MPa specified by BIS. So, We can also mix fly ash (at least 20% by weight of cement) in concrete as part replacement of cement at site. This is not only to save on material cost of concrete but also to achieve durable properties due to pore refinement (Less porous concrete). The concrete thus prepared also has increased workability and higher strength at later ages.
PPC (Fly Ash Based) Cement:
On the other hand, PPC (Portland Pozzolana Cement) is made up of 75 – 77% cement clinker, 20% flyash and 3-5% gypsum.
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.
Recommended use for OPC 53 Grade Cement:
Since it gains early strength and has cost saving advantages as discussed above, OPC 53 Grade cement is generally recommended for Structural Concrete or Reinforced Concrete Works (like Columns, Beams, Slab etc.,)
Recommended use for PPC:
Flyash based cement (PPC) is recommended for brick masonry, plastering, tiling and waterproofing works. In these works, strength is not the major criteria. 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).
PPC :
• Higher durability of concrete structure due to less permeability of water.
• More resistance towards the attack of alkalies, sulphates, chlorides, chemicals.
• Better work ability.
• Low heat of hydration.
• Due to high fineness, PPC has better cohesion with aggregates and makes more dense concreteness.
• Comparative lower Water-Cement ratio provides an added advantage for the further increase of compressive strength of the concrete.
• Better surface finish.
OPC43 :
• Produces highly durable and sound concrete due to very low percentage of alkalis, chlorides, magnesia and free lime in its composition.
• Almost negligible chloride content results in restraining corrosion of concrete structure in hostile environments.
• Significant saving in cement consumption while making concrete of grades M15, M20, M25, M35 and pre-cast segments due to high strength.
So here we discuss specifically about each type of cement.
OPC 53 Grade Cement:
OPC (Ordinary Portland Cement) is the basic form of cement with 95% cement clinkers and 5% being gypsum.
Gypsum is as an additive to increase the setting time of the cement to a workable 30 minutes or more.
OPC Cement gives high compressive strength at early ages and at 28 days. A 53 Grade cement gives up to 70 MPa strength against a minimum 53 MPa specified by BIS. So, We can also mix fly ash (at least 20% by weight of cement) in concrete as part replacement of cement at site. This is not only to save on material cost of concrete but also to achieve durable properties due to pore refinement (Less porous concrete). The concrete thus prepared also has increased workability and higher strength at later ages.
PPC (Fly Ash Based) Cement:
On the other hand, PPC (Portland Pozzolana Cement) is made up of 75 – 77% cement clinker, 20% flyash and 3-5% gypsum.
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.
Recommended use for OPC 53 Grade Cement:
Since it gains early strength and has cost saving advantages as discussed above, OPC 53 Grade cement is generally recommended for Structural Concrete or Reinforced Concrete Works (like Columns, Beams, Slab etc.,)
Recommended use for PPC:
Flyash based cement (PPC) is recommended for brick masonry, plastering, tiling and waterproofing works. In these works, strength is not the major criteria. 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).
PPC :
• Higher durability of concrete structure due to less permeability of water.
• More resistance towards the attack of alkalies, sulphates, chlorides, chemicals.
• Better work ability.
• Low heat of hydration.
• Due to high fineness, PPC has better cohesion with aggregates and makes more dense concreteness.
• Comparative lower Water-Cement ratio provides an added advantage for the further increase of compressive strength of the concrete.
• Better surface finish.
OPC43 :
• Produces highly durable and sound concrete due to very low percentage of alkalis, chlorides, magnesia and free lime in its composition.
• Almost negligible chloride content results in restraining corrosion of concrete structure in hostile environments.
• Significant saving in cement consumption while making concrete of grades M15, M20, M25, M35 and pre-cast segments due to high strength.
