Cement Flashcards
(97 cards)
1
Q
Who invented portland Cement
A
Joseph Aspidin, 1824
2
Q
What is the average particle size of cement
A
10-20 micrometre
3
Q
What is the meaning of soundness of cement
A
Ability to retain volume after setting
4
Q
Time elapsed from the instance of adding water until paste ceases to behave as fluid is called
A
Initial setting time
5
Q
What is the initial setting time of cement
A
30 minutes
As Per Is 4031 part 5
6
Q
Which of the following is the most commonly used type of cement?
a) Portland Pozzolana Cement (PPC)
b) Sulphate Resisting Cement
c) Ordinary Portland Cement (OPC)
d) Rapid Hardening Cement
A
Ordinary Portland Cement (OPC)
7
Q
Low-heat cement is generally used for:
a) Rapid construction
b) Massive concrete structures
c) Road construction
d) Precast concrete
A
Massive concrete structures
8
Q
Which cement is recommended for constructions exposed to marine conditions?
a) Sulphate Resisting Cement
b) Low Heat Cement
c) White Cement
d) Quick Setting Cement
A
Sulphate Resisting Cement
9
Q
White cement differs from Ordinary Portland Cement due to:
a) Lack of iron oxide
b) Lack of calcium silicate
c) Absence of gypsum
d) Presence of silica
A
Lack of iron oxide
10
Q
Which of the following is the primary ingredient in cement?
a) Silica
b) Lime
c) Alumina
d) Iron oxide
A
Lime
11
Q
Gypsum is added to cement to:
a) Increase strength
b) Prevent rapid setting
c) Increase workability
d) Improve color
A
Prevent rapid setting
12
Q
The main function of Alumina in cement is:
a) To provide strength
b) To impart quick setting properties
c) To enhance durability
d) To regulate the expansion
A
To impart quick setting properties
13
Q
The Tricalcium Silicate (C3S) in cement is responsible for:
a) Early strength
b) Long-term strength
c) Setting time
d) Reducing shrinkage
A
Early strength
14
Q
The process of heating raw materials to form clinker is called:
a) Pulverizing
b) Grinding
c) Calcination
d) Hydration
A
Calcination
15
Q
Which of the following raw materials is used in the production of cement?
a) Limestone
b) Sandstone
c) Clay
d) All of the above
A
All of the above
16
Q
The temperature required in the kiln during the manufacture of cement is approximately:
a) 500°C
b) 1000°C
c) 1450°C
d) 2000°C
A
1450°C
17
Q
The chemical reaction between cement and water is called:
a) Dehydration
b) Hydration
c) Polymerization
d) Crystallization
A
Hydration
18
Q
Which component of cement contributes the most to the setting process?
a) Dicalcium Silicate (C2S)
b) Tricalcium Silicate (C3S)
c) Tricalcium Aluminate (C3A)
d) Tetracalcium Aluminoferrite (C4AF)
A
Tricalcium Silicate (C3S)
19
Q
What is the main factor that influences the initial setting time of cement?
a) Particle size
b) Water-cement ratio
c) Curing temperature
d) Amount of gypsum
A
Amount of gypsum
20
Q
The strength of cement is tested using:
a) Slump test
b) Compression test
c) Tensile test
d) Shear test
A
Compression test
21
Q
Which method is commonly used for the manufacture of Portland cement?
a) Wet process
b) Dry process
c) Semi-dry process
d) All of the above
A
Dry process
22
Q
Pozzolanic cement contains a percentage of pozzolanic material, which typically ranges between:
a) 15% - 35%
b) 5% - 10%
c) 40% - 50%
d) 60% - 70%
A
15% - 35%
23
Q
The hydration of which compound in cement causes heat generation?
a) C3A
b) C3S
c) C2S
d) C4AF
A
C3S
24
Q
Which raw material is a primary component of cement production?
A) Sand
B) Water
C) Clay
D) Plastic
A
Clay
Clay is a primary component of cement production, as it provides the necessary silica, alumina, and iron oxide required for cement’s chemical composition.
25
The main chemical compound responsible for cement's strength is:
A) Calcium carbonate
B) Silica
C) Alumina
D) Tricalcium silicate
Tricalcium silicate
26
Which type of cement is suitable for use in marine structures?
A) Ordinary Portland Cement (OPC)
B) Rapid Hardening Cement
C) Sulphate Resistant Cement
D) White Cement
Sulphate Resistant Cement
27
Which type of cement is used to reduce the heat generated during hydration?
A) High Alumina Cement
B) Low Heat Cement
C) Quick-setting Cement
D) Blended Cement
Low Heat Cement
Low Heat Cement is used to reduce the heat generated during the hydration process, which is especially important in massive concrete structures to prevent cracks.
28
The compound responsible for the gray color of cement is:
A) Calcium oxide
B) Iron oxide
C) Aluminum oxide
D) Magnesium oxide
Iron oxide
29
Which type of cement is used in artistic and decorative applications?
A) Rapid Hardening Cement
B) Blended Cement
C) White Cement
D) Portland Pozzolana Cement (PPC)
White Cement
30
The standard consistency of cement paste is determined by the:
A) Vicat apparatus
B) Le Chatelier apparatus
C) Autoclave
D) Compaction test
Vicat apparatus
measures the amount of water required to achieve a standard consistency.
31
The property of cement that allows it to maintain its volume after setting is called:
A) Workability
B) Plasticity
C) Shrinkage
D) Autogenous healing
Autogenous healing
Autogenous healing is the property of cement that allows it to self-heal and maintain its volume after setting, which can help in sealing small cracks.
32
Which type of cement is used in cold weather conditions due to its ability to set quickly?
A) Portland Pozzolana Cement (PPC)
B) Quick-setting Cement
C) Low Heat Cement
D) Rapid Hardening Cement
Quick-setting Cement
33
The primary chemical compounds in cement responsible for its strength are:
A) C3S and C2S
B) C3A and C4AF
C) C2S and C3A
D) C4AF and C2S
C3S and C2S
34
What is the effect of an increased percentage of C3A in cement?
A) Increased early strength
B) Reduced heat generation
C) Improved workability
D) Increased susceptibility to sulfate attack
Increased susceptibility to sulfate attack
35
Which type of cement is used in high-temperature applications like foundries and furnace linings?
A) High Alumina Cement
B) Quick-setting Cement
C) Low Heat Cement
D) Portland Pozzolana Cement (PPC)
High Alumina Cement
High Alumina Cement is used in high-temperature applications due to its excellent resistance to heat and fire.
36
Which test is used to determine the soundness of cement?
A) Vicat test
B) Le Chatelier test
C) Setting time test
D) Fineness test
Le Chatelier test
The Le Chatelier test is used to determine the soundness of cement, which indicates its ability to resist volume changes after setting.
37
Which type of cement is used to prevent corrosion of steel reinforcement in concrete structures?
A) Sulphate Resistant Cement
B) Blended Cement
C) Portland Pozzolana Cement (PPC)
D) Ordinary Portland Cement (OPC)
Sulphate Resistant Cement
38
What is the minimum percentage of calcium sulfate (gypsum) that is added to cement during production?
A) 1%
B) 2%
C) 3%
D) 5%
2%
39
Which type of cement is used in the construction of dams and large hydraulic structures?
A) Low Heat Cement
B) Rapid Hardening Cement
C) Sulphate Resistant Cement
D) Blended Cement
Low Heat Cement
Low Heat Cement is used in the construction of dams and large hydraulic structures to control the heat generated during hydration and prevent cracks.
40
The fineness of cement is determined by:
A) Vicat apparatus
B) Le Chatelier apparatus
C) Blaine air permeability test
D) Compaction test
Blaine air permeability test
The fineness of cement is determined using the Blaine air permeability test, which measures the specific surface area of the cement particles.
41
What is the effect of adding too much water during cement mixing?
A) Increased strength
B) Reduced workability
C) Faster setting time
D) Reduced durability
Reduced workability
42
Which type of cement gains strength more slowly than Ordinary Portland Cement (OPC)?
A) Rapid Hardening Cement
B) Low Heat Cement
C) Sulphate Resistant Cement
D) Quick-setting Cement
Low Heat Cement
Low Heat Cement gains strength more slowly than Ordinary Portland Cement (OPC), making it suitable for mass concrete structures to prevent cracking due to heat.
43
The heat of hydration in cement is released during:
A) Mixing
B) Setting
C) Curing
D) Drying
Setting
44
Which type of cement is used for making precast elements and high-strength concrete?
A) Portland Pozzolana Cement (PPC)
B) Blended Cement
C) Rapid Hardening Cement
D) Sulphate Resistant Cement
Rapid Hardening Cement
Rapid Hardening Cement is used for making precast elements and high-strength concrete due to its early strength development.
45
. Which type of cement is produced by reducing the amount of C3A to prevent sulfate attack?
A) Rapid Hardening Cement
B) Low Heat Cement
C) Sulphate Resistant Cement
D) Portland Pozzolana Cement (PPC)
Sulphate Resistant Cement
Lower tricalcium aluminate (C₃A) content, as C₃A reacts with sulfates.
46
Which test measures the soundness of cement by subjecting it to high-pressure steam?
A) Vicat test
B) Le Chatelier test
C) Autoclave test
D) Compaction test
Autoclave test
The autoclave test measures the soundness of cement by subjecting it to high-pressure steam, simulating the conditions that can lead to volume changes.
47
Which type of cement is used in the construction of water-retaining structures and sewage systems?
A) Sulphate Resistant Cement
B) Blended Cement
C) Rapid Hardening Cement
D) Portland Pozzolana Cement (PPC)
Sulphate Resistant Cement
Sulphate Resistant Cement is used in the construction of water-retaining structures and sewage systems to resist the effects of sulfate attack.
48
The primary compound responsible for the setting of cement is:
A) Tricalcium silicate (C3S)
B) Dicalcium silicate (C2S)
C) Tricalcium aluminate (C3A)
D) Tetracalcium aluminoferrite (C4AF)
Tricalcium silicate (C3S)
49
What is the role of fineness in cement?
A) To enhance color
B) To control setting time
C) To increase strength
D) To reduce workability
To control setting time
Finer particles lead to faster setting, while coarser particles result in slower setting times.
50
Which type of cement is used for mass concrete structures like dams and foundations?
A) Rapid Hardening Cement
B) Low Heat Cement
C) Quick-setting Cement
D) Portland Pozzolana Cement (PPC)
Low Heat Cement
51
Which type of cement is used in the construction of roads and pavements?
A) Rapid Hardening Cement
B) Low Heat Cement
C) Sulphate Resistant Cement
D) Ordinary Portland Cement (OPC)
Ordinary Portland Cement (OPC)
52
What is the primary function of pozzolanic materials in blended cement?
A) Increasing setting time
B) Enhancing workability
C) Reducing heat of hydration
D) Improving color
Reducing heat of hydration
The primary function of pozzolanic materials in blended cement is to reduce the heat of hydration and improve durability.
53
Which type of cement is produced by adding a higher amount of alumina and ferric oxide?
A) High Alumina Cement
B) Low Heat Cement
C) Rapid Hardening Cement
D) Portland Pozzolana Cement (PPC)
High Alumina Cement
High Alumina Cement is produced by adding a higher amount of alumina and ferric oxide, making it suitable for high-temperature applications.
54
The process of grinding clinker, gypsum, and other materials to produce cement is called:
A) Hydration
B) Calcination
C) Clinkering
D) Blending
Clinkering
55
What is the effect of a higher percentage of C4AF in cement?
A) Increased strength
B) Reduced heat of hydration
C) Faster setting time
D) Improved workability
Reduced heat of hydration
56
Which type of cement is used for repairing structures due to its rapid setting characteristics?
A) Rapid Hardening Cement
B) Low Heat Cement
C) Quick-setting Cement
D) Sulphate Resistant Cement
Quick-setting Cement
57
Which type of cement is used in decorative concrete flooring and terrazzo finishes?
A) Blended Cement
B) White Cement
C) Quick-setting Cement
D) Low Heat Cement
White Cement
58
Vicat test
Consistency test - To determine the water content required to make a cement paste of standard consistency.
59
method to find the setting time of cement
Vicat test
The initial setting time is when the needle penetrates to 5 mm from the bottom, and the final setting time is when the needle makes no impression on the paste.
60
Setting Time
Initial setting time: Not less than 30 minutes.
Final setting time: Not more than 600 minutes (10 hours).
61
Compressive Strength Test
Cement mortar is prepared by mixing cement, sand, and water in the ratio of 1:3. The mixture is placed in cubes (50 mm or 70.6 mm), and the cubes are tested in a compression testing machine after curing for 3, 7, or 28 days.
62
Soundness Test
To ensure that the cement does not undergo significant volume changes after setting.
Le Chatelier apparatus is used for this test.
63
Which of the following is not an advantage of rapid hardening cement?
a) Faster construction
b) Short curing period
c) Light in weight
d) Higher final setting time
Higher final setting time
It develops the same strength of ordinary cement in four days rather than 28 days.
64
High alumina cement can be used for massive concrete work.
a) True
b) False
False
High alumina cement is obtained by adding 55% bauxite and 35-45% lime. It hardens rapidly and it is costlier. It cannot be used for massive concrete work.
65
How many types of cement are there based on the ability to set in presence of water?
a) 2
b) 3
c) 4
d) 5
2
The 2 types are hydraulic and non-hydraulic cement. Hydraulic cement sets and becomes adhesive due to reaction with water. Non-hydraulic cement does not set under-water or in wet conditions.
66
What property does air-entraining cement provide?
a) Workability
b) Soundness
c) Fineness
d) Strength
Workability
67
Which of the following types of cement is used in marine structures?
a) Expanding cement
b) High alumina cement
c) Blast furnace slag cement
d) White cement
Blast furnace slag cement
68
Which pair of the compound and coloured cement mentioned below is wrong?
a) Iron oxide-yellow
b) Cobalt-black
c) Chromium oxide-green
d) Manganese dioxide-brown
Cobalt : Blue
Iron oxide : Brown, Red, yellow
69
Chromium oxide provide which colour to cement
Green
70
Cobalt provide which colour to cement
Blue
71
For red colour, which compound isused in cement
Iron oxide
72
Manganese Oxide can impart ..... color to cement
Brown or Black
73
Which of the following is not a pozzolanic material?
a) Fly ash
b) Silica fume
c) Cinder
d) Slag
Cinder
Pozzolans are silicate based materials that form cementitious materials. Fly ash, silica fumes and slag are composed of oxide of silicon.
Cinder is a coal residue.
74
Water proof cement is prepared by mixing ordinary cement with:
a) Resins
b) Water repellent chemicals
c) Sulpho-aminate
d) Metal stearates
Metal stearates
Resins: air entraining cement.
Water repellent chemicals: hydrophobic cement.
Sulpho-aminate : expanding cement.
Metal stearates (Ca, Al, etc) : water proof cement.
75
Deficiency of lime in cement leads to:
a) Unsound cement
b) Disintegration of cement
c) Quick setting of cement
d) Expansion of cement
Quick setting of cement, reduced strength
76
What effect does calcium sulphate have on cement?
a) Retards setting action
b) Acts as flux
c) Imparts colour
d) Reduces strength
Retards setting action
CaSo4 :Gypsum
77
Which of the following adds a quick-setting property to cement?
a) Magnesium oxide
b) Silicon dioxide
c) Iron oxide
d) Aluminium oxide
Aluminium oxide
78
Which of the following imparts greenish grey colour to cement?
a) Calcium silicate
b) Calcium aluminate
c) Calcium aluminate ferrite
d) Calcium carbonate
Calcium aluminate ferrite
79
Excess of Alkali in cement results in:
a) Dry cement paste
b) Efflorescence
c) Less plasticity
d) Unsound cement
Efflorescence
Efflorescence is the formation of powdery substance on the surface of masonry or concrete work. Alkalis usually get carried away by flue gases during heating. In excess quantity, they result in alkali-aggregate reaction.
80
What function does iron oxide perform in cement?
a) Increases strength
b) Makes cement sound
c) Increases setting time
d) Acts as flux
Acts as flux
Iron oxide acts as a flux, in addition to being responsible for imparting colour to cement. If the temperature goes higher, then iron oxide reacts with aluminium and calcium and results in the formation of calcium aluminate ferrite.
81
How many major ingredients are present in the composition of cement?
a) 8
b) 5
c) 10
d) 6
8
lime, silica, alumina, magnesia, iron oxide, calcium sulphate, sulphur trioxide and alkalis.
82
Sulphur in cement is present in what amount?
a) 0.5 – 6 g
b) 1 – 2.5%
c) 0.5 – 6%
d) 1 – 2.5g
1 – 2.5%
83
An excess of magnesium oxide after 5% is harmful to cement.
a) True
b) False
True
Excess of magnesium causes problems in structures built with this cement. It causes cracks in both mortar and concrete after they harden.
84
Nowadays, wet method of cement manufacturing is used.
a) True
b) False
False
Wet method was used from 1913 to 1960. The dry method is most adopted because it improves the quality of cement, utilizing less power.
85
How is the argillaceous material used in the manufacture of cement stored?
a) Silos
b) Basins
c) Bags
d) Storage tanks
Basins
Clay is the argillaceous material used. These are mixed with water thoroughly and washed in a container-wash mill. The wet mixture is then stored in basins.
86
What is released during the production of clinker?
a) CaCO3
b) CO2
c) Ca(OH)2
d) CO
CO2
87
What is the advantage of using precalciner?
a) Fine grained cement
b) Larger clinker size
c) Fuel efficiency
d) Sound cement
Fuel efficiency
Almost 95% of calcination is completely over in the precalciner, if 50-60% of fuel is added to this chamber. Hence fuel in the kiln required is less.
88
What does grade 33 cement indicate?
a) Tensile strength of 33 kN/m2
b) Tensile strength of 33 N/mm2
c) Compressive strength of 33 kN/m2
d) Compressive strength of 33 N/mm2
Compressive strength of 33 N/mm2
The grades of cement are specified by IS 1489-1991. Cements are usually graded based on their compressive strength.
89
Ordinary Portland cement (OPC) has been classified into how many grades?
a) 2
b) 3
c) 10
d) 5
3
33 grade, 43 grade and 53 grade.
90
Grade 43 OPC is used widely for:
a) High rise buildings
b) Plastering
c) House construction
d) Finishing works
House construction
Grade 33 used for finishing works under normal condition.
Grade 53 is used for high rise building.
91
After how many days is the strength of cement is tested and graded according to the result?
a) 7 days
b) 28 days
c) 1 day
d) 14 days
28 days
92
The compressive strength of OPC increases with time:
a) True
b) False
True
Strength of 43 grade OPC at the end of 3 days is 23, 7 days is 33 and 28 days is 43
93
Grade 43 OPC shall be rejected if it remains in bulk storage in the factory for:
a) More than 3 months
b) More than 1 month
c) More than 6 months
d) More than 4 months
More than 6 months
94
The ratio of percentage of alumina to iron oxide in OPC 43 grade is:
a) 3.5
b) 0.66
c) 0.1
d) 0.05
0.66
95
What is the required minimum fineness for grade 53 OPC?
a) 370 m2/kg
b) 370 cm2/g
c) 580 m2/kg
d) 580 cm2/g
370 m2/kg
96
Which of the following cannot be added in 33 grade OPC after burning stage?
a) Gypsum
b) Water
c) Colouring Agents
d) Clay
Clay
=
97
