Additives that affect the properties of gypsum
There are limitations to the improvement of gypsum slurry performance by a single admixture. If you want to achieve satisfactory performance of gypsum mortar and meet different application requirements. You need chemical admixtures, admixtures, fillers and multiple materials to complement each other and compound them scientifically and rationally.

01.Setting regulator

Set regulators are mainly divided into retarders and accelerators. In gypsum dry-mixed mortar, products prepared with gypsum use retarders. And products prepared with anhydrous gypsum or directly using dihydrate gypsum require accelerators.

02.Retarders

Adding retarders to gypsum dry-mixed building materials inhibits the hydration process of hemihydrate gypsum and prolongs the setting time. There are many factors that affect the hydration of gypsum. Including the phase composition of gypsum, the temperature of gypsum materials when preparing the product, the particle fineness, the setting time and the pH value of the prepared product.

Each factor has a certain influence on the retarding effect. So there is a large difference in the amount of retarder used in different situations.

03.Coagulant

Accelerating the mixing time of slurry and extending the mixing speed of slurry are both physical coagulation methods. Commonly used chemical coagulants in anhydrous gypsum powder building materials include acidic substances such as potassium chloride, potassium silicate, and sulfate. The dosage is generally 0.2% to 0.4%.

04.Water-retaining agent

Gypsum dry-mixed building materials cannot do without water-retaining agent. Improving the water retention rate of gypsum product slurry is to ensure that water can exist in the gypsum slurry for a long time, so as to obtain a good hydration and hardening effect.
Improving the construction performance of gypsum powder building materials. Reducing and preventing the segregation and bleeding of gypsum slurry. Improving the sag of slurry. Extending the open time. And solving engineering quality problems such as cracking and hollowing are inseparable from water-retaining agent.
Whether the water-retaining agent is ideal mainly depends on its dispersibility, solubility, moldability, thermal stability and thickening, among which the most important indicator is water retention.
Additives that affect the properties of gypsum(Ⅱ)