During the mixing process of adding water to the dry-mixed mortar, the air is wrapped by the wet mortar to form air bubbles. At the same time, additives such as water reducer, redispersible polymer powder and cellulose ether have hydrophilic groups, which can reduce the surface tension of the water, make the bubbles to gather and increases the stability of the bubbles.

For mortar products (such as self-leveling mortar, waterproofing mortar, etc.), the microbubble air content of 3%~6% is the best.

Uniform and stable small air bubbles help to improve the workability of the mortar, enhance the frost resistance and other durability of the mortar, etc.

The increase of large bubbles will increase the porosity of the mortar and reduce the mechanical properties of the mortar. Especially for mortar products with waterproofing requirements, it is inevitable to suppress and defoam the mortar.

The effect of defoamer on wet density of mortar

 Defoamer KDO 8803 can inhibit the formation of air bubbles and destroy the formed air bubbles in mortar. Therefore, adding a defoamer KDO 8803 to the mortar product can reduce the air content of the mortar and increase the wet density of the mortar. There are certain differences in the effects of different types of defoamers, but within a certain range, the wet density of mortar increases with the increase of the amount of defoamer; when the amount of defoamer reaches a certain value, the wet density of mortar tends to be stable .

The effect of defoamer on the fluidity of mortar

Defoamers KDO 8803 can improve the initial fluidity of mortar, and different types of defoamers have different effects on fluidity. An effective defoamer like KDO 8803 not only destroys the bubbles quickly, but also prevents the regeneration of the bubbles for a considerable period of time.

The effect of defoamer on the mechanical properties of mortar

Defoamer KDO 8803 can improve the compressive and flexural strength of mortar by eliminating harmful air bubbles in mortar, reducing the porosity of mortar and improving the pore structure of cement, but it will not increase after reaching a certain value.  

Defoamer is used to eliminate harmful air bubbles inside cement-based materials, and has a wide range of application values in concrete and mortar. In dry-mixed mortar, the defoamer is mainly used for self-leveling mortar, which can eliminate the air bubbles introduced by admixtures such as redispersible polymer powder and water reducer during the mixing process, so that the hardened floor material is smooth and flat, and the surface of the material is reduced. porosity for increased durability.