Gypsum Self-leveling Mortar Additive Cellulose Ether

Overview of Gypsum-based Self-leveling Mortar

1. Performance Characteristics:
   • High construction efficiency, saving labor costs.
   • Good dimensional stability, much better crack resistance than cement-based mortar, suitable for thick-layer construction.
   • Fast setting and hardening, even under low winter temperatures, normal setting and hardening can occur.
   • Has thermal insulation function.

Gypsum-based Self-leveling Mortar with Additives Additives can adjust the mortar’s consistency, regulate the overall water usage, and improve the mortar’s water retention. The water requirement in the gypsum mortar system is a crucial parameter. Gypsum-based self-leveling mortar uses methyl cellulose ether as a water-retaining agent to adjust the water requirement and yield of the gypsum mortar, control the mortar’s workable time, and enhance the bond between leveling mortar and substrate.

Cellulose Ether

1. Cellulose ether is a general term for a series of cellulose derivatives produced from natural cellulose under certain conditions through alkalization and etherification reactions, where hydroxyl groups on the cellulose molecular chain are replaced by ether groups.
2. Special cellulose ether for self-leveling mortar, such as cellulose ether 400E, has the following characteristics:
   • Low viscosity, ensuring the flowability of the mortar.
   • Reduces the water sensitivity of the mortar, minimizes bleeding and water exudation, and improves the surface strength and abrasion resistance after the mortar hardens.
   • High gel temperature, providing excellent water retention for the mortar.
   • Widely adaptable to different cement-based and gypsum-based self-leveling mortars.

Polycarboxylate Water Reducer

1. Definition of water reducer: An admixture for concrete that, under the condition of maintaining the basic consistency of concrete slump, reduces the amount of mixing water.
2. Functions of water reducer: 1) Maintains constant water content while increasing the fluidity of the slurry; 2) Reduces water consumption, lowers the water-to-cement ratio, and enhances the slurry’s density and strength.
3. Characteristics of gypsum-specific water reducer:
   • Higher performance requirements than water reducers used for cement.
   • High water reduction rate in gypsum, and a small amount can significantly improve the flowability of gypsum-based self-leveling mortar.
   • Good universality, suitable for various gypsum and gypsum-dominant mortar systems.
   • Excellent adaptability to gypsum, does not cause severe water exudation, and has no adverse effects on gypsum setting, hardening, and strength.

Gypsum Retarder

1. Gypsum hydration characteristics: Rapid setting and hardening, losing plasticity within minutes after mixing with water.
   • Hydration process consists of 5 stages: initial, induction, acceleration, deceleration, and final.
2. Functions of gypsum retarder:
   • Effectively extends the setting time of gypsum, determining the workable time of gypsum-based materials during construction or molding.
   • Has a significant impact on the strength after gypsum hardening, with different retarders affecting gypsum in various ways.
   • Delays the acceleration stage of gypsum hydration, reduces the peak heat release, and postpones its occurrence. Different retarders influence gypsum crystal morphology and microstructure, affecting gypsum strength.
   • Delays the setting of gypsum without affecting its degree of hydration.
3. Protein-based high-efficiency gypsum retarder: Derived from protein through chemical modification.
   • Excellent retarding effect.
   • Increases the linear setting time of gypsum linearly with the addition of the retarder, enhancing product stability.
   • Odorless.
   • Good powder flowability, anti-caking performance.
   • Good adaptability, suitable for various gypsum systems.
   • Stable quality.