Post Date:19,May,2025
(1) Improve bond strength, tensile strength and flexural strength.
The redispersible polymer powder can significantly improve the bond strength of mortar, and the greater the addition amount, the better the improvement effect, but the compressive strength will decrease, so there is an optimal addition amount range. Due to the high price of redispersible polymer powder, the greater the amount added, the higher the cost of dry-mixed mortar, so it is also necessary to consider the cost. High bond strength has a certain inhibition effect on shrinkage, and the stress generated by deformation is easy to disperse and release, so the bond strength is very important to improve the cracking resistance. The results show that the synergistic effect of cellulose ether and polymer powder can improve the bond strength of cement mortar.
(2) Reduce the elastic modulus of the mortar, so that the brittle cement mortar has a certain flexibility.
The elastic modulus of the redispersible polymer powder is low, ranging from 0.001 to 10GPa. The elastic modulus of cement mortar is relatively high, ranging from 10 to 30GPa, so the addition of polymer powder will reduce the elastic modulus of cement mortar. However, the type and dosage of polymer powder also affect the elastic modulus. Generally, with the increase of polymer cement ratio, the elastic modulus decreases and the deformation ability increases.
(3) Improve water resistance, alkali resistance, wear resistance and impact resistance.
The network membrane structure formed by the polymer seals the holes and cracks in the cement mortar, reduces the porosity of the hardened body, and improves the permeability resistance, water resistance and frost resistance of the cement mortar. The effect was enhanced with the increase of polymer cement ratio. The improvement of wear resistance is related to the type of polymer powder and the ratio of polymer cement. In general, as the polymer cement ratio increases, the wear resistance increases.
(4) Improve the fluidity and constructability of mortar.
(5) Improve the water retention of mortar and reduce water evaporation.
The polymer emulsion formed by the redispersible polymer powder dissolved in water is dispersed in the mortar, and a continuous organic film is formed in the mortar after curing. This layer of organic film can prevent the migration of water, thereby reducing the loss of water in the mortar and playing the role of water retention.
(6) Reduce cracking phenomenon.
The elongation and toughness of polymer modified cement mortar are much better than that of ordinary cement mortar, and the fracture property is more than twice that of ordinary cement mortar. And the impact toughness increases with the increase of cementing ratio. With the increase of the amount of polymer powder added, the flexible buffer effect of the polymer can inhibit or delay the development of cracks, and it has a good stress dispersion.
Post time: May-19-2025