BUILDING MATERIALS
- CEMENT
A cement is a binder, a substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Concrete is the most widely used material in existence and is only behind water as the planet's most-consumed resource.
Cements used in construction are usually inorganic, often lime or calcium silicate based, which can be characterized as non-hydraulic or hydraulic respectively, depending on the ability of the cement to set in the presence of water.
Non-hydraulic cement does not set in wet conditions or under water. Rather, it sets as it dries and reacts with carbon dioxide in the air. It is resistant to attack by chemicals after setting.
Hydraulic cements (e.g., Portland cement) set and become adhesive due to a chemical reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble and so are quite durable in water and safe from chemical attack. This allows setting in wet conditions or under water and further protects the hardened material from chemical attack. The chemical process for hydraulic cement was found by ancient Romans who used volcanic ash (pozzolana) with added lime (calcium oxide).
cement full details
include
1. introduction
2. Types of cement
3. Tests for cement
4. raw materials of cement
5. manufacturing of cement
DOWNLOAD THE WORD FILE
The first part of video include Raw materials for cement and their properties
The second part include process of manufacturing of cement
The third part include properties of cement
ie 's
- physical properties
- chemical properties
The fourth part include test to be done for finding properties of the cement..
two properties
- field test
- lab test
The fifth part of cement include types of cement and their properties
13 types cement available
Previous kerala psc question are available
cement part 1
1. The main constituents of cement is ***
a)Lime
b)Silica
c)Alumina
d)calcium sulphate
ans a) lime
2 ) The ingredient that imparts quick setting property to
cement is *
a)Alumina
b)Silica
c)Gypsum
d)Lime
ans: a) Alumina
3. A good quality cement should have higher percentage of
a)Silica
b)Free lime
c)Di calcium silicate
d)Tri calcium silicate
ans : d) Tri calcium
silicate
4) The cementing property in cement in mainly due to
a)Silica
b)Lime
c)Iron oxide
d)Alumina
Ans: b) lime
5) The silica in portland cement should be
a)20 to 25%
b)10 to 20%
c)25 to 40%
d)40 to 60%
Ans: a) 20 to 25%
6) Silica is melt at ………… oC.
a) 1730 oC.
b) 1400 oC
c) 1430 oC
d) 1510 oC
Ans: a) 1730 oC
7) Alumina is :
a)Al2O3
b)Al2SO4
c)Al2O3SiO3
d)Al2K2SO4
Ans: a) Al2O3
8) Cement contains ………% of lime.
a)55
b)3
c)62
d)75
Ans: c) 62
9) The function of
gypsum in cement is :
a)To increase strength
b)To increase initial
setting time
c)To decrease initial
setting time
d)To increase final
setting time
ans: b) To increase initial setting time
10) Which of the following is an ingredient present both in
cement and brick.
a)Iron oxide
b)Magnesium
c)Alumina
d)Alkalies
Ans : c) Alumina
11) The chemical constituents of silica in portland cement is ….
a)15 to 20%
b)17 to 20%
c)17 to 25%
d) 15 to 25%
Ans : c) 17 to 25%
12)The major ingredient of portland cement are..
a)Lime 62% and silica
22%
b)Lime 68% and silica
32%
c)Silica and alumina
d)Lime and iron
Ans: a) lime 62% and
silica 22%
13) Total water soluble sulphate content of the
concrete mix, expressed as SO3 ,by the mass of cement should not exceed:
a)3%
b)4%
c)5%
d)6%
Ans: b)4%
14) Chemical formula of dicalcium silicate
a) 2CaOSiO3
b) 2CaOSio2
c) CaOSiO2
d) 2CaOSiO4
Ans : a) 2CaOSiO3
15) The compound formed within about 24 hours after the
addition of water to cement is
a)Tricalcium aluminate
b)Dicalcium aluminate
c)Dicalcium silicate
d)Tricalcium silicate
Ans: a) Tricalcium aluminate
A cement is a binder, a substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Concrete is the most widely used material in existence and is only behind water as the planet's most-consumed resource.
Cements used in construction are usually inorganic, often lime or calcium silicate based, which can be characterized as non-hydraulic or hydraulic respectively, depending on the ability of the cement to set in the presence of water.
Non-hydraulic cement does not set in wet conditions or under water. Rather, it sets as it dries and reacts with carbon dioxide in the air. It is resistant to attack by chemicals after setting.
Hydraulic cements (e.g., Portland cement) set and become adhesive due to a chemical reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble and so are quite durable in water and safe from chemical attack. This allows setting in wet conditions or under water and further protects the hardened material from chemical attack. The chemical process for hydraulic cement was found by ancient Romans who used volcanic ash (pozzolana) with added lime (calcium oxide).
cement full details
include
1. introduction
2. Types of cement
3. Tests for cement
4. raw materials of cement
5. manufacturing of cement
DOWNLOAD THE WORD FILE
The first part of video include Raw materials for cement and their properties
The second part include process of manufacturing of cement
The third part include properties of cement
ie 's
- physical properties
- chemical properties
The fourth part include test to be done for finding properties of the cement..
two properties
- field test
- lab test
The fifth part of cement include types of cement and their properties
13 types cement available
Previous kerala psc question are available
cement part 1
1. The main constituents of cement is ***
a)Lime
b)Silica
c)Alumina
d)calcium sulphate
ans a) lime
2 ) The ingredient that imparts quick setting property to
cement is *
a)Alumina
b)Silica
c)Gypsum
d)Lime
ans: a) Alumina
3. A good quality cement should have higher percentage of
a)Silica
b)Free lime
c)Di calcium silicate
d)Tri calcium silicate
ans : d) Tri calcium
silicate
4) The cementing property in cement in mainly due to
a)Silica
b)Lime
c)Iron oxide
d)Alumina
Ans: b) lime
5) The silica in portland cement should be
a)20 to 25%
b)10 to 20%
c)25 to 40%
d)40 to 60%
Ans: a) 20 to 25%
6) Silica is melt at ………… oC.
a) 1730 oC.
b) 1400 oC
c) 1430 oC
d) 1510 oC
Ans: a) 1730 oC
7) Alumina is :
a)Al2O3
b)Al2SO4
c)Al2O3SiO3
d)Al2K2SO4
Ans: a) Al2O3
8) Cement contains ………% of lime.
a)55
b)3
c)62
d)75
Ans: c) 62
9) The function of
gypsum in cement is :
a)To increase strength
b)To increase initial
setting time
c)To decrease initial
setting time
d)To increase final
setting time
ans: b) To increase initial setting time
10) Which of the following is an ingredient present both in
cement and brick.
a)Iron oxide
b)Magnesium
c)Alumina
d)Alkalies
Ans : c) Alumina
11) The chemical constituents of silica in portland cement is ….
a)15 to 20%
b)17 to 20%
c)17 to 25%
d) 15 to 25%
Ans : c) 17 to 25%
12)The major ingredient of portland cement are..
a)Lime 62% and silica
22%
b)Lime 68% and silica
32%
c)Silica and alumina
d)Lime and iron
Ans: a) lime 62% and
silica 22%
13) Total water soluble sulphate content of the
concrete mix, expressed as SO3 ,by the mass of cement should not exceed:
a)3%
b)4%
c)5%
d)6%
Ans: b)4%
14) Chemical formula of dicalcium silicate
a) 2CaOSiO3
b) 2CaOSio2
c) CaOSiO2
d) 2CaOSiO4
Ans : a) 2CaOSiO3
15) The compound formed within about 24 hours after the
addition of water to cement is
a)Tricalcium aluminate
b)Dicalcium aluminate
c)Dicalcium silicate
d)Tricalcium silicate
Ans: a) Tricalcium aluminate
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