Construction Defoamer Powder

The application of defoaming agent is closely related to the scene of high strength, durability and apparent quality of building materials:

Concrete: This is the most widely used and largest application area of defoaming agent. Adding defoaming agent in concrete production can effectively eliminate large bubbles, optimize pore structure, and significantly improve the mechanical properties (compressive and flexural strength) and durability (water resistance and freeze-thaw resistance) of concrete. At the same time, it makes the surface of the component more dense and glossy, eliminating honeycomb and pockmarked surfaces.

Dry mortar: widely used in self-leveling mortar, tile adhesive, waterproof mortar, putty, grouting material, etc. In these materials, defoaming agent can eliminate the bubbles introduced by latex powder, water reducer and other admixtures in the mixing process, improve the flow value, compressive strength and surface smoothness of mortar.

Other building materials: also used in the production of calcium silicate board, asbestos tile and other cement products, as well as in the field of paint, gypsum products and other areas of defoaming.

To ensure the defoaming agent achieves optimal performance, the following points are crucial:

Recommended dosage: Generally, the dosage is 0.1% -0.8% of the total weight of the powder material, and the specific dosage should be determined by experiments.

Add method:

The powder defoaming agent can be mixed with cement, sand and other dry powder materials directly.

Liquid defoaming agent: can be used directly or diluted with a small amount of water and added to the mixing water (note: emulsion-type defoaming agent should be diluted with cold water, hot water may cause demulsification). After addition, stir for a longer time to ensure uniform dispersion.

Important Notes:

Test before use: The defoaming agent is highly targeted. When using it for the first time or changing the material formula, a small sample test must be conducted to confirm its compatibility with the system and the optimal dosage.

Note the sequence of addition: In concrete, sometimes the process of "first defoaming then air entraining" is adopted, that is, defoaming agent is added first to eliminate harmful large air bubbles, and air entraining agent is added later to introduce stable small air bubbles, which can improve the workability of concrete.

Storage conditions: Store in a cool, ventilated place (10-30℃ recommended), avoid direct sunlight, freezing and high temperature.

The most common problems of using defoaming agent are mainly due to its characteristics and the conditions of using.

The most common reason for poor or failed defoaming is the incompatibility with the system. In addition, excessive dilution or violent shaking may destroy the stability of the emulsion, leading to demulsification and stratification. Exceeding the recommended dosage may also increase the viscosity of the slurry due to excessive defoaming, affecting the construction performance.

Causes surface defects: In mortar or coating, if the defoaming agent is not evenly dispersed, it may cause local tension difference, resulting in shrinkage hole, fish eye and other surface defects.

The effect of the defoaming agent on the workability of mortar: In concrete, the defoaming agent can eliminate the harmful air bubbles, but also may cause the slurry to become viscous and the fluidity to decrease. In this case, the mix proportion should be adjusted by experiment or the defoaming agent should be used in combination with the air-entraining agent.

Construction defoaming agent effectively eliminates harmful bubbles, significantly enhancing the strength, durability, and surface quality of building materials. To fully leverage its advantages, it is crucial to determine the optimal dosage through testing, ensure uniform dispersion, and pay attention to compatibility with other system components.