Application of redispersible latex powder in self-leveling mortar
Self-leveling mortar is a new type of building mortar material that has been vigorously promoted in recent years. During construction, it relies on its own weight and self-leveling properties to form a smooth, high-strength, wear-resistant, and economical base layer after curing. Self-leveling mortar boasts advantages such as good fluidity, ease of application, fast leveling speed, time-saving, thin leveling layer thickness, high surface flatness, and high compressive strength, effectively solving problems such as poor flatness and sanding associated with traditional flooring materials. The application of redispersible latex powder in self-leveling mortar represents a significant breakthrough in cement-based self-leveling technology. In cement-based self-leveling materials, redispersible latex powder improves flowability and increases cohesion, preventing bleeding and segregation. As a rheology modifier, redispersible latex powder exhibits outstanding bonding strength, improving adhesion, flexural strength, water resistance, plasticity, wear resistance, and workability, while also giving cement-based self-leveling materials greater flexibility and deformability.
The Effect of Redispersible Latex Powder Dosage on Flowability and 20-Minute Flowability
Redispersible latex powder typically lubricates mortar during application, protects the water affinity of the dispersed colloid, and increases the cohesion of the mortar due to viscosity, thereby improving workability. The effect of redispersible latex powder on mortar flowability changes with increasing dosage. When the dosage reaches 2%, the self-leveling mortar achieves a flowability of 155 mm; the flowability is excellent, with no bleeding on the surface, and the surface finish after leveling is good. When the powder dosage reaches 3%~4%, the flowability tends to decrease, and the 20-minute retention time also decreases. This indicates that a higher powder dosage results in higher viscosity, which has a certain impact on flowability.
The Influence of Redispersible Latex Powder on Bond Strength
In the construction of self-leveling mortar, the self-leveling layer is a secondary additional layer, and it is either uncured or has a very short curing time. Experiments show that adding a certain amount of latex powder provides long-term reliable adhesion. The bond strength of the self-leveling mortar increases significantly with the increase of the redispersible latex powder content. Moreover, the bond strength failure occurs within the polystyrene board, rather than at the interface, indicating good adhesion.
The Effect of Redispersible Latex Powder on Flexural and Compressive Strength
Under constant experimental conditions, the compressive-flexural ratio (compressive strength/flexural strength) of cement-based mortar gradually decreases with increasing redispersible latex powder content. This indicates that the brittleness of self-leveling flooring materials gradually decreases with increasing redispersible latex powder content, reducing the elastic modulus and improving crack resistance, reflecting an improvement in the mortar's flexibility.
The Influence of Redispersible Latex Powder on Abrasion Resistance
The addition of redispersible latex powder significantly improves abrasion resistance. With increasing dosage, the abrasion resistance of the mortar increases, and the abrasion resistance value decreases, indicating that the addition of redispersible latex powder provides excellent abrasion resistance for cement mortar. The film-forming properties in cement self-leveling mortar are also excellent, ensuring its overall performance. The addition of redispersible latex powder improves the fluidity of self-leveling mortar, increasing its abrasion resistance after hardening while reducing the possibility of cracking. Adding latex powder to self-leveling mortar significantly improves its various properties, increasing its flexural and compressive strength and enhancing its adhesion to the substrate. The unique advantages of latex powder, such as low dosage, good plasticizing effect, good reinforcing effect, and increased abrasion resistance, help solve the technical challenges of self-leveling mortar formulation.
