concrete air entraining agent AE369

2021年9月18日product 240

Controlled Air Entrainment
- Generates 5–8% stable, uniformly distributed air bubbles (typical dosage: 0.01–0.1% by cement weight).
- Bubble size: 10–300 μm, optimized to resist coalescence during mixing and placement.
Freeze-Thaw Resistance
- Creates air-void spacing factor <0.2 mm (critical for mitigating ice expansion pressure).
- Achieves >300 freeze-thaw cycles (ASTM C666 Grade F300), essential for cold climates (e.g., highway pavements in Nordic regions).
Improved Workability
- Reduces slump loss and friction between particles, enhancing pumpability and finishability.
- Maintains cohesion in low-water-content mixes (e.g., high-strength concrete).
Durability Enhancement
- Reduces bleeding and segregation, minimizing surface scaling and cracking.
- Lowers permeability by creating discontinuous capillary pores.

Chemical Composition
- Common types: Sulfonated lignins, synthetic surfactants (e.g., alkyl ether sulfates), or natural resins (e.g., Vinsol resin).
- Function: Lower surface tension at the air-water interface to stabilize bubbles.
Bubble Stability
- Bubbles remain intact during mixing, transportation, and vibration due to robust interfacial films.
- Resists collapse under high-pressure pumping or prolonged agitation.
Compatibility with Other Admixtures
- Synergizes with superplasticizers (e.g., polycarboxylate ethers) without compromising air content.
- May require dosage adjustments when used with accelerators or retarders.

Critical for Harsh Environments: Extends service life of concrete exposed to deicing salts or seawater.
Cost-Effective: Minimal dosage (0.005–0.05% by cement weight) delivers significant durability improvements.
Versatility: Suitable for ordinary and high-performance concrete (e.g., bridges, dams, airport runways).

Issue	Cause	Solution
Excessive air content	Overdosing or improper mixing	Optimize dosage via trial mixes; use automated dosing systems.
Strength reduction	High air content (>8%) lowers compressive strength	Balance air content with strength requirements (e.g., limit to 5–6% for structural concrete).
Incompatibility with some cements	High alkali or C₃A content in cement destabilizes bubbles	Use cement with moderate alkali levels; select AEA type (e.g., synthetic surfactants for high-C₃A cements).

Cold-Weather Concrete: Roads, bridges, and parking garages in freeze-thaw-prone regions.
Marine Structures: Ports, offshore platforms (resists chloride ingress).
Decorative Concrete: Improves surface finish and reduces plastic shrinkage cracks.