A single admixture has limitations in improving the performance of gypsum slurry. If you want to achieve satisfactory performance of gypsum mortar and meet different application requirements. Chemical admixtures, admixtures, fillers and multiple materials are required to complement each other. Scientifically and reasonably compounded.
1. Coagulation regulator
Coagulation regulators mainly divide into retarders and accelerators. In gypsum dry-mixed mortar, retarders are used in products formulated with plaster of paris. Products formulated with anhydrite or directly with dihydrate gypsum require a coagulant.
Adding retarder to gypsum dry-mixed building materials inhibits the hydration process of hemihydrate gypsum and prolongs the setting time. There are many factors for the hydration of plaster of paris. Including the phase composition of the plaster, the temperature of the plaster material when preparing the product, the fineness of the particles, the setting time and the pH value of the prepared product, etc. Each factor has a certain influence on the retarding effect, so there is a big difference in the amount of retarder in different situations.
At present, the best retarder for gypsum in China is the modified protein (high protein) retarder. It has the advantages of low cost, long retarding time, small loss of strength, good product construction, and long opening time. The amount used in the preparation of bottom-layer stucco plaster is generally 0.06% to 0.15%.
Accelerating the slurry stirring time and prolonging the slurry stirring speed are one of the methods of physical coagulation acceleration. Commonly used chemical coagulants in anhydrite powder building materials include potassium chloride, potassium silicate, sulfate and other acid substances. The dosage is generally 0.2% to 0.4%.
1.What admixtures are used for gypsum mortar?(2)
2.What admixtures are used for gypsum mortar?(3)
3.What admixtures are used for gypsum mortar?(4)