What is Pozzolana?
A silica material with little or no cement properties reacts with calcium hydroxide at ambient temperature to form compounds possessing cement properties. Pozzolana materials are natural volcanic ash, fly ash produced by combustion of coal and calcined clay. Any of these materials can be used in manufacturing Portland Pozzolana Cement.
How is Portland Pozzolana Cement (PPC) Produced?
PPC is produced in two ways
- Grinding together portland cement clinker and pozzolana materials with the addition of gypsum or calcium sulfate.
- Blending Portland cement and fine Pozzolana materials.
What is Portland Pozzolana Cement (PPC)?
When Portland cement clinker is mixed with pozzolanic materials, the result is PPC. PPC produces less heat of hydration and offers greater resistance to the aggressive waters attacks than ordinary Portland cement (53 and 43-grade cement). Moreover, it reduces the leaching of calcium hydroxide liberated during the setting and hydration of cement. It is particularly useful in marine and hydraulic construction and other mass concrete structures.
Portland-pozzolana cement can generally be used wherever 33 grade ordinary Portland cement is usable under normal conditions. However, it should be appreciated that all pozzolana need not necessarily contribute to strength at early ages.
Initial Setting time is 30 minutes and the final setting time is 600 minutes.
PPC achieves a compression strength of 16 MPa in 3 Days, 22 MPa in 7 Days and 33 MPa in 28 Days.
- Reduces water demand.
- Increases work-ability.
- Improves rheology of the mix
- Enhances water retention.
- Increases cohesiveness & pump-ability.
- Reduces internal bleeding and segregation.
- Reduces plastic shrinkage.
- Better slump retention.
- Reduces danger to honeycombing.
- Better surface finish.