Adding certain admixtures and fillers to gypsum materials can change part of the properties of gypsum products, adapt gypsum products to different conditions, different environments, and different uses, and enable gypsum dry-mixed building materials to perform better. Here are 12 types Take admixtures and fillers as examples, analyze the role and addition amount of various admixtures and fillers in gypsum-based products:

1. Portland cement: mainly use cement and gypsum to generate ettringite in the hydration reaction process to improve the strength, softening coefficient and bonding effect of gypsum products. The usage amount is generally between 1% and 12%.

2. Quicklime powder: Adding a small amount of quicklime powder to gypsum can change the setting time of gypsum, improve the strength and water resistance of gypsum products, and also improve its frost resistance. It can improve the workability of gypsum slurry and reduce water consumption. ; The usage is generally between 1%~10%.

3. Blast furnace slag powder: adding quicklime powder, cement and cement clinker into gypsum products can increase the strength and water resistance of gypsum hardened bodies and improve the workability of gypsum dry-mixed building materials. The usage amount is generally 10% to 30%.

4. Fly ash: Adding less than 20% has little effect on the strength and setting time of gypsum powder building materials, but it can improve the workability of gypsum slurry. For example, under proper alkaline excitation conditions, the later strength and water resistance of the hardened gypsum body can be significantly improved, and the usage amount is generally 0.5% to 30%.

5. Bentonite: It is the cheapest water-retaining and thickening material in gypsum dry-mixed building materials, but the amount should not be too much, otherwise it will affect the strength. The dosage is generally 0.3%~1%.

6. Zeolite powder: It can improve the workability of gypsum dry-mixed mortar, reduce mud bleeding, improve flowability, and improve frost resistance. It has the effect of thickening and strengthening. The dosage is generally 1%~3%.

7. Mica: Incorporated into some products of gypsum dry-mixed mortar, it can improve the dry flexural strength of the product, and has heat insulation, sound insulation, light weight, crack resistance, and reduced shrinkage. The dosage is generally 0.5%~2%.

8. Gray calcium and heavy calcium (double fly powder): used for gypsum dry mixed mortar as a filler to improve the fluidity of gypsum. The general dosage is 5%~40%.

9. Kaolin: Adding gypsum dry-mixed building materials can improve the water retention and cohesiveness of the slurry, and compounding fly ash can improve the fluidity of the slurry, and the general mixing amount is 1% to 3%.

10. Mineral insulation materials: sepiolite, expanded vermiculite, perlite, vitrified microspheres, etc. can all be called mineral insulation materials. In gypsum dry-mixed building materials, it is suitable for gypsum light mortar and gypsum insulation compound, which can improve the workability of plastered gypsum products, increase water retention, and change the function of sound insulation. The usage is generally 5%~45%.

11. Mineral reinforcing materials: Inorganic mineral fibers can improve the crack resistance and flexural strength of dry-mixed gypsum building materials, and replace part or all of wood fibers and polypropylene fibers. The general dosage of inorganic mineral fiber is 1%~5%.

12. Aggregate: The aggregate contains quartz sand and construction sand, whether it is natural sand, artificial sand, or quartz sand. The quality requirement is mainly that the mud content must be small. Generally, the mud content must be controlled below 4%. The gradation surface should be large. When preparing the bottom plaster gypsum, it is best to use graded sand for the self-leveling gypsum mortar, which has high strength, good fluidity, non-segregation, low bleeding, good water retention, and good workability. In general bonding gypsum and gypsum mine filling materials, medium and fine sand should be selected for better effect; it is better to use fine quartz sand in fast-bonding gypsum and caulking gypsum. The dosage is generally 30%~70%.

Gypsum-based products are more and more widely used. At present, the market is mainly desulfurized gypsum and phosphogypsum, which can be used as the following mortars: light plastering gypsum mortar, light machine sprayed gypsum mortar, heavy gypsum mortar, caulking gypsum , Gypsum white leveling mortar, gypsum binder, gypsum gypsum, gypsum putty and other building materials.