The document discusses various aspects of gypsum products, including the properties and characteristics of hydrated and dehydrated forms. It covers topics such as setting time, expansion types, and manipulation techniques, along with the theories related to hydration and dissolution. Additionally, it highlights the relationship between water-to-powder ratio, setting expansion, and setting time.

1. GYPSUM PRODUCTS
PART - 2
Dr.shiva

2. Recap

3. • Hydrated(dihydrate) • Dehydrated(hemihydrate) • Rehydrated • Dihydrate(dehydration)

4. Gypsum products
ADA specification
number
Manufacturing
Open
Close
properties
Mixing time
Setting time
Working time
Final set
Initial set
Measuring of
setting time
Vicat
Gillmore needle
Loss of gloss
Exothermic heat
Setting reaction Classification Uses of gypsum

5. DIMENSIONAL CHANGES

6. TwoTypes of Expansions
• Normal setting expansion
• Hygroscopic setting expansion

7. HOW ARE
PARTIALSTHIS
GOINGTO
PUSHED EACH
OTHER??
Hemihydrate Dihydrate

8. Normal
setting
expansion

9. Hygroscopic
setting
expansion

11. COMPOSITION

14. Hemihydrate
Hemihydrate sol
Dihydrate sol
Dihydrate gel

16. Hydration theory

19. Dissolution precipitation theory / crystalline theory

20. Setting reaction

22. Strength

24. What is die ? What is FPD ?

29. Thank you
Drshivasai

30. MIND MAPPING

31. Gypsum products part -2
Dimensional
changes
Types of
expansions
Normal stetting
expansion
Hygroscopic setting
expansion
Difference
between
expansions
Manipulation Composition Theories
Colloidal theory
Hydration theory
Dissolution
precipitation theory
Strength of
gypsum
Relations
b/w
w:p &setting expansion &
setting time
Die
Recent
advances

32. MANIPULATION