Lime Flashcards
1
Q
What is Lime?
A
Cementitious material (binding material)
2
Q
Chemical formula of Lime
A
CaO
3
Q
Chemical formula of limestone
A
CaCO3
4
Q
How is lime obtained from limestone
A
by heating limestone, the process is called calcination
5
Q
Classification of binding materials
A
- Air binding
- Hydraulic Binding
- Autoclave Binding
6
Q
Conditions in Autoclave binding?
A
8-12 atm
170 C to 200 C
7
Q
Sources of Lime
A
- Limestone (riverbeds, boulders in hills)
- Seashells (Small quantities)
- Kankar (impure lime available below ground)
8
Q
Constituents of Lime
A
- Clay (8-30%)
- Soluble Silica
- Magnesium Carbonate (<30%)
- Alkalies and Metallic Oxides (<5%)
- Sulphate
- Iron
- Pyrites (impurities)
9
Q
Classifications of Lime
A
- Fat lime
- Hydraulic Lime
- Poor Lime
10
Q
Characteristics of Fat Lime
A
- low impurities (<5%)
- slow hardening and setting
- Slaking is vigorous
- sp. gravity is about 3.4
11
Q
Fat lime is also known as
A
pure lime, white lime, rich lime, high calcium lime
12
Q
Uses of Fat lime
A
- mortar
- plastering
- white washing
13
Q
What is Hydraulic Lime
A
- Lime that sets in Water
14
Q
Types of Hydraulic Lime
A
- Feebly hydraulic lime
- Moderately hydraulic lime
- Eminently hydraulic lime
15
Q
Characteristics of Feebly hydraulic lime
A
- Clay content : 5-10%
- Slake time : few mins
- Setting time : 3 weeks
- Strength : low
- Uses : Plaster, whitewash (damp places for less imp. structures)
