Correct Answer - Option 4 : Increases bleeding
Explanation:
Air entraining admixture:
These are the type of admixture that entrains millions of air bubbles in voids of concrete, which act as flexible ball bearing and slip pass over each other thereby modify almost every property of concrete.
These are nowadays used as the fifth ingredient in the preparation of concrete.
Commonly used air-entraining admixture includes:
- Aluminum powder
- Hydrogen peroxide
- Plants and animals fatty acid
- Natural wood resin
- Olic and ferric acid
These admixture effects following properties:
- Increase resistance to freezing and thawing
- Increase workability
- Reduces strength
- Reduce tendency of segregation and bleeding
- Decreases permeability
- Increases resistance to chemical attack
- Reduce unit weight and alkalies aggregate reaction