1. 4.2.4.1 Chemical Admixture 4.2.4.2 Mineral Admixture
4.2.4 Concrete Admixture
Chemical Admixture
Introduction
Water-Reducing Admixture
Hardening Accelerator
Air Entraining Admixture
Set Retarding Admixture
Flash Setting Admixture
Expanding Admixture
Frost-resistance Admixture
Mineral Admixture

2. Air Entraining Admixture
Definition
Mechanism
Performance
Improving durability
Improving workability
Decreasing concrete strength
Application
Common air entraining admixture

3. Air Entraining Admixture
Definition
It refers to the concrete admixture that is added bubbles with:
large quantities
separate
independent
tiny
even
Definition

4. Air Entraining Admixture
Mechanism
It is the hydrophobic apparent active substance
Reduce the surface tension
Cause the oriented adsorption in the bubble surface
Change the air in the course of mixing into separate, tiny and even bubbles

5. Air Entraining Admixture
Performance
Improving durability
Improving workability
Decreasing concrete strength
Air entraining admixture can improve durability and plasticity, but it reduces strength.

6. How Properties Improved
Air entraining admixtures
Change the pore structure, improve durability
Increase lubricate of aggregates, improve plasticity
Increase air content, reduce strength
Connected pores
Air entraining admixtures
Closed pores
Fig Sketch map of improve durablity

7. Air Entraining Admixture
Application
This type of admixture should always be used in freezing and thawing deterioration.
It reduces the strength unnecessarily in structural concrete.

8. Common Air Entraining Admixture
Rosin soap and rosin pyrolytic polymer and so on
the amount 0.005%-0.012%
introducing D= mm air bladder
making concrete air content to 2%-6%
Common Air Entraining Admixture