Defoamer

Defoamers are developed using the latest patented technology and are synthesized from polyether and other components. It is suitable for the defoaming and stabilizing effect of cement-based material systems under strong alkaline conditions. At a pH of 14, it does not break the emulsion, does not float oil, has good defoaming and foam suppression effects, can eliminate harmful bubbles, stabilize beneficial bubbles, and is non-toxic, odorless, and will not cause any pollution to the environment.

Defoamers are additives used in concrete to control and reduce the formation of foam and air bubbles during mixing and pouring. Excess foam and entrapped air can weaken the concrete’s strength and durability, so defoamers help improve the final quality of the concrete.

Types of defoamers used in concrete include:

1. Oil-based Defoamers: These contain light oils or mineral oils that spread on the surface of foam and cause it to break down.
2. Surface-active Agents (Surfactants): These reduce the surface tension of foam, causing it to collapse.
3. Silicone-based Defoamers: These are highly effective and are commonly used in concrete to rapidly eliminate foam.

Uses:

• Reduce air entrapment during mixing.
• Improve surface finish.
• Enhance the strength and durability of concrete.

Application:

• Added directly to the concrete mix.
• Applied during mixing or as a part of admixture formulations.

When using air-entraining agents and defoamers together, certain principles must be followed. First, the purpose of use must be clearly defined to ensure that the simultaneous application of these two admixtures balances their effects. This approach guarantees adequate air content in concrete to enhance its freezing resistance and water resistance while eliminating excess air bubbles to improve concrete strength and surface quality. Second, products should be selected appropriately, including choosing air-entraining agents and defoamers with good compatibility and considering their performance characteristics. Finally, the appropriate dosage ratio must be determined to ensure both admixtures function stably and effectively within the concrete system.

🔸 Experimentation is essential to identify the optimal dosage ratio between air-entraining agents and defoamers. During testing, gradually adjust the dosage of each while closely monitoring concrete performance metrics such as air content, bubble elimination, workability, and strength.
🔸 Typically, air-entraining agent dosage should be moderate to avoid introducing excessive air bubbles, which would increase the burden on the defoamer. Simultaneously, defoamer dosage must be controlled within reasonable limits to prevent over-defoaming that could lead to insufficient air content in the concrete, thereby compromising critical properties like freezing resistance.

Timing of Addition: Defoamers can be incorporated at different stages during concrete mixing. For instance, they may be added early in the mixing process alongside other admixtures, or introduced later when excessive air bubbles appear to eliminate them.
🔸The dosage of defoamer must strictly adhere to the product instructions and project requirements. Excessive use may adversely affect other properties of the concrete.
Mixing Requirements:
🔸Adding defoamer to concrete typically does not require extending the mixing time. However, thorough mixing is essential to ensure the defoamer rapidly acts on air bubbles within the concrete for effective elimination.