What are the special properties of redispersible latex powder in mortar?
What properties of mortar can be improved by redispersible latex powder?
⑴ Redispersible latex powder improves the bonding strength, tensile and flexural strength of the material
Redispersible latex powder can significantly improve the bonding strength of mortar. The greater the amount of redispersible latex powder, the more redispersible latex powder manufacturers can increase, but the compressive strength of redispersible latex powder decreases, so it can There is an optimal range for the redispersed latex powder. Since the price of redispersible latex powder is higher, the larger the amount, the higher the cost of dry-mixed mortar, so the cost must be considered. The high bond strength has a certain inhibitory effect on the shrinkage, and the stress generated by the deformation of the redispersible latex powder is easy to disperse and release. Therefore, the bond strength is very important to improve the crack resistance. Studies have shown that the synergistic effect of redispersible latex powder cellulose ether and rubber powder is beneficial to improve the bonding strength of cement mortar.
⑵Reduce the elastic modulus of the mortar, and the price of redispersible latex powder can make the brittle cement mortar have certain flexibility
The elastic modulus of the redispersible latex powder performance is lower, 0.001-10 GPa, while the elastic modulus of cement mortar is higher, 10-30 GPa. The redispersible latex powder manufacturer can reduce the elastic modulus of cement mortar after adding rubber powder. However, the type and amount of rubber powder also affect the elastic modulus. Generally, the ash accumulation ratio increases, the elastic modulus decreases, and the deformability increases.
⑶ Redispersible latex powder improves water resistance, alkali resistance, abrasion resistance and impact resistance of mortar
The network membrane structure formed by the polymer closes the holes and cracks in the cement mortar, and the redispersible latex powder reduces the porosity in the hardened body, thereby improving the impermeability, water resistance and frost resistance of the cement mortar. The effect increases as the ash accumulation ratio increases. The redispersible latex powder improves the abrasion resistance of the mortar and is related to the type of rubber powder and the aggregate ash ratio. Generally speaking, the higher the dust-gathering ratio, the higher the wear resistance.
⑷Redispersible latex powder improves the fluidity and workability of mortar
⑸ Redispersible latex powder improves the water retention of mortar and reduces water evaporation
The emulsion formed by dissolving the redispersible latex powder in water is dispersed in the mortar. After solidification, the redispersible latex powder will form a continuous organic film in the mortar. This organic film can prevent the migration of water, thereby reducing the mortar Loss of water plays a role in water retention.
(6) Redispersible latex powder reduces cracking
The elongation and toughness of polymer-modified cement mortar are much better than that of ordinary cement mortar, and its fracture performance is more than twice that of ordinary cement mortar. The impact toughness increases with the increase of the polymer-cement ratio. With the increase of the amount of rubber powder, the flexible cushioning effect of the polymer can inhibit or delay the development of cracks, and at the same time has a better stress dispersion effect.
According to the different proportions, the use of dispersible polymer powder to modify dry-mixed mortar can improve the bonding strength with various centralized sources, and improve the flexibility and variability, bending strength, and abrasion resistance of the mortar. , Resistance and adhesion, as well as water retention capacity and workability.