Hydrophobic agents are a class of admixtures that prevent moisture from entering the mortar while also keeping the mortar open to allow water vapor to diffuse.
Water repellent includes three product series: fatty acid metal salts, silanes, and special hydrophobe re-dispersible polymer powders.
The unit cost of the fatty acid metal salt product series is relatively low, but its main disadvantage is that it takes a long time to mix the mortar with water evenly. The typical dosage is 0.2% to 1% of the cement dosage.
The special powdered silane product series exhibits high hydrophobicity and can mix quickly and evenly with mortar. Silane can form a highly durable bond with the hydration products of cement in an alkaline environment. Typical dosage 0.1%～0.5% of cement dosage
Special hydrophobic re-dispersible polymer powder product series can provide good hydrophobicity but require a higher dosage. The typical dosage is 1% to 3% of the cement dosage. These polymers can also improve the mortar’s adhesion, cohesion, and flexibility.
Thixotropic lubricant
Thixotropic lubricant is a pure, inorganic, flaky silicate additive specially processed for dry-mixed powder and paste systems.
The raw material of thixotropic lubricant is mainly silicate containing montmorillonite. Montmorillonite has a three-layered ore with a dioctahedral crystal structure with intracrystal swelling ability. These layers The structure formed by the swelling silicate can increase the essential viscosity of the system. The structure can be reversibly destroyed when the shear force exceeds the limit (yield value). The formation of the yield value can improve the stability of the mortar, overcome adverse effects such as mortar sagging or agglomeration, and be used in the construction of thick-layer mortar. It can also significantly improve the storage resistance of paste mortar and the anti-sedimentation of self-leveling systems, prevent the precipitation of additives and pigments and inhibit seepage, color, and secretion.
When the mortar is stirred, pumped, or scraped, the weak shear force is enough to overcome the yield value, and the lamellar silicate acts as a lubricant, reducing the relative viscosity and thus improving the workability of the mortar.
Thixotropic lubricant mainly improves the workability, opening time, and consistency of cement-based systems, increase the workability and sag resistance of mortars, plasters, primers, plastering mortars and adhesives, and the delamination of waterproof self-leveling cement.
The thixotropic lubricant series products are divided into general-purpose and special-purpose types. To meet different construction methods and application fields, other product models are suitable for different mortar products, such as self-leveling mortar, decorative mortar, masonry mortar, plastering mortar, gray mortar, exterior wall insulation mortar, adhesive, sealing mortar, caulking agent, and jointing agent.
