Air Entraning powder
- Product Name: Air-entraining Agent
- Alternative name: Air Entrainer
- Appearance: powder, liquid
- Applications: high-performance durable concrete structures including dams, high-grade highways, cooling towers at thermal power stations, water tanks, ports and more
- Packaging: Liquid(200kg/IBC Tank, 1000kg/IBC Tank); powder(25kg paper bag)
Air-entraining Agent, also know as air entrainer, is a hydrophobic surfactant. Our company provides a general-purpose air-entraining agent in concrete, which is an anionic surfactant. Its interfacial activity mainly occurs at the gas-liquid interface, which significantly reduces the surface tension and interfacial energy of water. When it is dissolved in water, it can be added to the concrete mixture. During the mortar mixing process, the air-entraining agent can produce a large number of tiny bubbles, which are evenly distributed in the concrete to form a stable tiny bubble structure. Air entrainer is a concrete additive that can reduce the surface tension of the mixing water in the mortar, thereby leading to better dispersion and reducing the bleeding and segregation of the mortar concrete mixture. In addition, the introduction of tiny and stable air bubbles can improve the construction performance. The amount of air introduced depends on the type of mortar and the mixing equipment used.
| Detection Index | AE-302 | AE-02 |
| Appearance | Transparent to light yellow liquid | White to light yellow powder |
| Bulk density (g/l) | 1-1.2 | 400-600 |
| Active ingredients (%) | 28 | 99 |
| Dosage | Should be added at a minimal dosage of 0.001% to 0.3% by total weight of components. The actual dosage should be determined through suitable tests prior to production and application. | |
| Storage | Under condition 5-35°C, dry and cool. Prevent direct sunlight, moisture and be pressed for caking. | |
| Packaging | 200kg/drum, 1000kg/ IBC tank | 25kg paper bag |
Roles of Air-entraining Agent in Concrete
Improve the workability of concrete. The addition of air-entraining agent forms a large number of tiny closed bubbles in the concrete mixture. These bubbles can reduce the friction resistance between aggregate particles and increase the fluidity of concrete. At the same time, since the water is evenly distributed on the surface of a large number of bubbles, the amount of free-moving water is reduced, and the water retention and cohesion of the concrete are improved.
Improve the durability of concrete. The bubbles introduced by the air-entraining agent can cut off the capillary passage, weaken the capillary action, and enhance the impermeability of concrete. In addition, these tiny pores can release the expansion pressure of ice crystals during the freezing process, prevent the generation of destructive pressure, thereby reducing the freeze-thaw destructive effect and improving the frost resistance of concrete.
Improve the crack resistance of concrete. The presence of bubbles slightly reduces the elastic modulus of concrete, which is beneficial to the crack resistance of concrete. However, bubbles also reduce the stress area of concrete, thereby reducing the strength and wear resistance of concrete.
Reduce bleeding and segregation. The liquid air entraining admixture can effectively reduce the bleeding and segregation of concrete and improve its homogeneity.
How Does Air Entrainer Work?
Most of the air-entraining agents are anionic surfactants. At the water interface, the hydrophobic base is directional adsorbed toward the air. At the cement-water interface, cement or its hydrated particles are adsorbed with the hydrophilic base, and the hydrophobic base deviates from the cement and its hydrated particles to form a hydrophobic adsorption layer, and tries to get close to the air surface. As the particles approach the air surface and the air-entraining agent molecules are adsorbed on the air-water interface, the surface tension of water will be significantly reduced, resulting in a large number of fine bubbles being generated during the concrete mixing process. These bubbles carry directional adsorption layers with the same charge, so they repel each other and can be evenly distributed.
On the other hand, many anionic air-entraining liquid have calcium salt precipitation in high-calcium cement aqueous solutions, which adsorb on the bubble membrane and can effectively prevent the bubbles from bursting. The introduced small and uniform bubbles can exist stably for a certain period of time.
The interfacial activity of air-entraining agents is similar to that of water-reducing agents. The difference is that the interfacial activity of water-reducing agents mainly occurs at the liquid-solid interface, while the interfacial activity of air-entraining agents mainly occurs at the gas-liquid-solid interface.
