Application of RDP in mixed mortar

Redispersible latex powder (RDP) is a key additive for high-performance dry-mixed mortar systems. It is widely used in products such as tile adhesive, self-leveling mortar, plastering mortar, repair mortar and external insulation system (EIFS/ETICS), significantly improving the workability, adhesion, mechanical properties and durability of mortar.

Core characteristics and functions:

Enhance bonding strength: RDP forms a flexible polymer film after hydration and hardening, and synergizes with the cement matrix to greatly improve the interfacial adhesion between mortar and various substrates (such as low water absorption substrates) and covering layers (ceramic tiles, insulation boards).

Improve flexibility and crack resistance: The polymer film gives the mortar excellent flexibility and deformation ability, effectively absorbs the stress caused by temperature changes or micro-deformation of the substrate, and significantly reduces the risk of cracking. It is especially suitable for occasions with high crack resistance requirements (such as EIFS plaster layer and repair mortar).

Optimize construction performance: RDP improves the workability, lubricity and plasticity of mortar, making it easier to spread, smooth and shape, reducing construction resistance and improving work efficiency.

Improve durability:

Water resistance/alkali resistance: The polymer film provides hydrophobicity, reduces water absorption, and remains stable in alkaline cement environments, extending service life.

Wear resistance/impact resistance: Enhances mortar density and improves resistance to mechanical wear and impact, suitable for floor mortar, etc.

Synergistic water retention and shrinkage control: The protective colloid and polymer particles in RDP help retain water, extend the open time, promote full hydration of cement, and reduce early shrinkage cracking, which is particularly important for thin layer construction.

Main application areas:

Tile adhesive: Improve initial adhesion, final strength and flexibility, suitable for large-size tiles and difficult-to-bond substrates.

Plastering mortar: Enhance substrate adhesion and crack resistance, compatible with various bases such as concrete, masonry, and insulation boards.

External Insulation System (EIFS): Improve the adhesion, flexibility and weather resistance of bonding mortar and plastering mortar.

Self-leveling mortar/repair mortar/waterproof mortar: Improve fluidity, wear resistance, adhesion, water resistance and structural ductility.

Key points for use:

Suitable dosage: Optimize the addition ratio according to application requirements (typical range 2%-6%).

Storage conditions: Avoid high temperature and high humidity environment to prevent agglomeration or performance degradation.

Synergistic effect: Pay attention to the compatibility with other additives such as cellulose ether (HPMC), defoamer, coagulant, etc.

Conclusion:

Redispersible latex powder (RDP) fundamentally improves the bonding performance, deformation adaptability, workability and durability of mixed mortar by forming a flexible polymer network. It is an indispensable functional component of modern high-performance and special dry-mixed mortar. It plays a core role in promoting the development of green building materials and meeting diversified construction needs, and has broad application prospects.