Correct Answer - Option 4 : Statement (I) is false but Statement (II) is true
Pozzolonic material is essentially Celicious or Aluminous compound which is itself do not posses any cementing property , but when finely grinded in presence of water, it reacts with Calcium Hydroxide released during hydration of the cement and leads to formation of cementous compounds.
Examples of Pozzolonic material are:
Blast Furnace Slag, Rice husk ash, Surkhi (powdered brick), fly-ash charcoal etc.
Portland Pozzolana cement is the cement prepared by intergrading cement clinkers with pozzolonic material (10 – 15 %).
The following are the some characteristics of Portland Pozzolana cement:
1. Higher water tightness.
2. Higher resistance against expansion.
3. Higher plasticity.
4. Higher resistance against attack of chlorides and sulphates.
5. Lower the rate of development of strength i.e it decreases early strength but ultimate strength is comparable with ordinary Portland cement.
6. Low heat of hydration.