What is the initial setting time of PPC cement?

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What is the initial setting time of PPC cement?

Setting time of PPC us higher than OPC. Its initial setting time is 30 minutes and final setting time is 600 minutes. Its slower setting time helps to get better finishing.

What is the initial and final setting time of ordinary Portland cement?

The time at which cement completely loses its plasticity and became hard is a final setting time of cement. The time taken by cement to gain its entire strength is a Final setting time of cement. For Ordinary Portland Cement, The Final Setting Time is 600 minutes (10hrs).

What is Portland Pozzolana cement?

PPC is a type of blended cement. 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. …

Where is Portland Pozzolana cement used?

Uses of Portland Pozzolana Cement Used in hydraulic structures, marine structures, construction near the sea shore, dam construction etc. Used in pre-stressed and post-tensioned concrete members. Used in masonry mortars and plastering. As it gives better surface finish, it is used in decorative and art structures.

What is initial setting time?

Initial setting time is the time when the paste starts losing its plasticity. Initial setting time test is important for transportation, placing and compaction of cement concrete. It is the time taken for the cement paste or cement concrete to harden sufficiently and attain the shape of the mould in which it is cast.

Is PPC cement good for RCC?

Both OPC and PPC cements are good for construction of concrete slab. PPC is used where possibilities of sulphate attack is higher as it has good sulphate resistance compared to OPC. Also pozzolana Portland cement is cheaper than ordinary Portland cement.

What is the initial setting time of cement * 1 point 1 hour 30 minutes 15 minutes 30 hours?

What is the initial setting time? Explanation: The time at which cement paste loses its plasticity is known as initial setting time of the concrete. Explanation: As per IS specification, the minimum initial setting time is 30 minutes for ordinary portland cement.

How long does it take for Portland cement to set?

Concrete typically takes 24 to 48 hours to dry enough for you to walk or drive on it. However, concrete drying is a continuous and fluid event, and usually reaches its full effective strength after about 28 days.

Why is pozzolana added to cement?

What does a pozzolan do in the concrete? A. Pozzolans reduce bleeding because of fineness; reduce the maximum rise in temperature when used in large amounts (more than 15% by mass of cementitious material) because of the slower rate of chemical reactions; which reduce the rise in temperature.

What are the advantages of Portland Pozzolana cement?

Portland pozzolana cement (PPC) has following advantages when concrete is in its hardened state.

  • Compressive Strength & Rate of Strength Gain.
  • Modulus of Elasticity.
  • Bond of Concrete to Steel.
  • Heat of Hydration.
  • Reduced Shrinkage.
  • Permeability.

What are the advantages of pozzolana Portland cement?

Advantages of Portland Pozzolana Cement (PPC):

  • It is economical as in PPC a part (25%) of costly clinker of OPC is replaced by cheaper pozzolanic material.
  • Improvement in permeability as soluble calcium hydroxide is converted into insoluble cementitious product.

Is the initial setting time of cement?

The time elapsed between the moments when water is added to the cement to the time when the square needle penetrates a depth of 33 to 35 mm from the top of the mould is known as the Initial Setting Time of that cement. The initial Setting Time should not be less than 30 minutes for Ordinary Portland Cement.

How long does it take to dry Portland pozzolana cement?

This clinker is now mixed with gypsum and pozzolana materials in the required proportion and thus the Portland Pozzolana Cement is obtained. Final setting time = 600 min (maximum). Drying shrinkage should not be more than 0.15%

How are the modules of Portland pozzolana cement formed?

The modules formed from the burning process called clinker. The clinker is cooled by a rotary cooler. This clinker is now mixed with gypsum and pozzolana materials in the required proportion and thus the Portland Pozzolana Cement is obtained.

What is the hydration level of pozzolana cement?

The fineness of pozzolana cement must not be much less than 300 m 2 /kg. PPC cement has a strong compressive strength and can cross 13 MPa in 3 days, 22 MPa in 7 days and 33 MPa in 28 days. The hydration and hydration levels of PPC cement are low, which is due to the variety and quantity of mixed materials.

Why was pozzolana used as a building material?

Pozzolana is a very old building material that was also used in Roman times. Portland Pozzolana cement is a type of low heat cement because it produces much less heat of hydration, it has better resistance to an aggressive water attack. This reduces the leaching of calcium hydroxide when used in hydraulic constructions.

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