How Much is the Suitable Dosage of Redispersible Polymer Powder in Polymer Mortar?

Redispersible polymer powder is an important additives in polymer drymix mortar. How much do you add the polymer powder in your production to get the best performances? 
 

The changes of redispersible polymer powder’s dosage has obvious influence on the flexural strength of polymer mortar. When dosage of redispersible powder is 3%, 6% and 10%, which can increase the flexural strength of fly ash-metakaolin polymer mortar by 1.8, 1.9 and 2.9 times, respectively. The ability of fly ash-metakaolin polymer mortar to resist deformation increases with increasing of the dosage of redispersible latex powder. When dosage of latex powder was 3%, 6% and 10%, the flexural toughness of fly ash-metakaolin polymer increased by 0.6, 1.5 and 2.2 times, respectively.
 

Redispersible polymer powder significantly improves the flexural and bond tensile strength of cement mortar, thereby improving the flexibility of cement mortar and enhancing the bond tensile strength of the interface zone of cement mortar-concrete and cement mortar-EPS plate systems.
When the cement ratio is 0.3-0.4, the fracture elongation of polymer modified cement mortar jumps from less than 0.5% to close to 20%, thus making the material change from rigid to flexible. Further increasing the polymer content can obtain more excellent flexibility.

Increasing the amount of redispersible powder in mortar can improve the flexibility. When the amount of polymer powder is about 15%, the flexibility of mortar has a significant change. When the dosage is higher than this, the flexibility of mortar increases with the increasing of the amount of polymer powders. Through the bridge crack capacity and transverse deformation test, it is found that with the increase of redispersible polymer powder dosage(from 10% to 16%), the flexibility of mortar increases gradually, the dynamic bridge crack capacity (7d) increases from 0.19mm to 0.67mm, and the transverse deformation (28d) increases from 2.5mm to 6.3mm. At the same time, it is found that the increase of redispersible polymer powder dosage can slightly increase the anti-seepage pressure of the surface of the mortar, and reduce the water absorption of the mortar. With the increase of redispersible latex powder dosage, the long-term water resistance of mortar gradually decreases. When the dosage of redispersible latex powder is adjusted to 10%-16%, the modified cement-based slurry can obtain good flexibility, but also has excellent long-term water resistance.