Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CMT > Cement Introduction > Flashcards

Cement Introduction Flashcards

1
Q

What is the primary function of cement?

A

Cement binds sand and rocks into a matrix.

Cement and concrete are often used synonymously, but they are different materials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is hydraulic cement?

A

A cement which possesses the property of hardening in combination with water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the raw materials used to manufacture Portland cement?

A
  • Lime
  • Silica
  • Alumina
  • Iron oxide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Tricalcium silicate (C3S) responsible for in Portland cement?

A

Hydrates and hardens rapidly, responsible for initial set and early strength.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What role does gypsum play in Portland cement?

A

Gypsum is added to retard hydration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Who is Joseph Aspdin?

A

A bricklayer and mason who patented hydraulic cement called Portland cement in 1824.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is hydration in the context of hydraulic cement?

A

The process where water mixed with Portland cement causes chemical reactions that lead to hardening.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the five types of Portland cement according to ASTM C150?

A
  • Type I - Ordinary Portland Cement
  • Type II - Moderate Heat Cement
  • Type III - High Early Strength Cement
  • Type IV - Low Heat Cement
  • Type V - High Sulfate Resistance Cement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the purpose of Type II Portland cement?

A

Generates less heat during curing and is more resistant to sulfate attack.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the characteristic of Type III Portland cement?

A

Formulated to gain strength quickly, ideal for fast-setting projects.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is Pozzolan?

A

A siliceous and aluminous material that reacts with calcium hydroxide to form cementitious compounds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is bleeding in concrete?

A

Appearance of water on the surface of concrete after it has consolidated but before it is set.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the problems associated with bleeding in concrete?

A
  • Delays finishing operation
  • High water-cement ratio
  • Poor bond between layers
  • Poor pumpability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are solutions to reduce bleeding in concrete?

A
  • Use more fines by adding pozzolan
  • Adjust grading of aggregates
  • Introduce entrained air
  • Reduce water content
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the purpose of entrained air in concrete?

A

To create tiny air bubbles that increase durability and workability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Fly Ash?

A

A byproduct from burning pulverized coal in electric power plants, used as pozzolan.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the ASTM C618 classification for Fly Ash?

A
  • Class C - High lime content, self-cementing
  • Class F - Low lime content, purely pozzolanic
18
Q

What is GGBFS?

A

Ground Granulated Blast Furnace Slag, a replacement for Portland cement.

19
Q

What is the main advantage of using Type V Portland cement?

A

Provides superior protection against sulfate attack.

20
Q

What is the effect of Tricalcium aluminate (C3A) in Portland cement?

A

Hydrates quickly and liberates a large amount of heat, contributing to early strength.

21
Q

What does the term ‘calcination’ refer to in cement production?

A

The process that restructures molecular composition in the kiln.

22
Q

What is the typical percentage of portland cement in total mass of cementitious material?

A

Between 25 and 70%

This percentage varies based on specific applications and formulations.

23
Q

What is a fundamental quality control issue for cement producers?

A

Proper hydration of portland cement

Specifications control quality but do not guarantee concrete quality.

24
Q

What factors influence the quality of concrete made with cement?

A

Mix design, quality control, characteristics of mixing water and aggregates

All these factors interact to determine the final concrete quality.

25
How is fineness of cement expressed?
As the specific surface of cement ## Footnote Fineness is a measure of particle size and affects strength gain.
26
What is the relationship between fineness of cement and hydration rate?
Higher fineness increases the rate of hydration ## Footnote More surface area is available for chemical reactions.
27
What are the two levels that describe the setting of cement?
Initial set and final set ## Footnote These levels indicate the transition of cement paste from plastic to solid state.
28
What is the initial set time required for handling concrete?
Must allow for handling and placing before maximum final set time ## Footnote This ensures proper workability before stiffening occurs.
29
What is the effect of gypsum in cement manufacturing?
Regulates the setting time ## Footnote Gypsum slows down the rate of aluminate hydration.
30
What happens if there is an excess of aluminate and sulfate ions in cement?
Workability stage may last only 10 minutes and setting may occur in 1 to 2 hours ## Footnote High aluminate and low sulfate can lead to quick or flash setting.
31
What is a false set in cement?
Cement stiffens within minutes without significant heat evolution ## Footnote It can be remedied by vigorous remixing.
32
What does soundness of cement refer to?
Ability of cement paste to retain its volume after setting ## Footnote Expansion after setting indicates unsound cement.
33
What test is used to check the soundness of cement paste?
Autoclave expansion test (ASTM C151) ## Footnote This test measures expansion under heat and pressure.
34
How is compressive strength of mortar measured?
By preparing 50-mm cubes and subjecting them to compression according to ASTM C109 ## Footnote This involves using standard sand and measuring strength at different ages.
35
What is the heat of hydration?
The quantity of heat liberated during complete hydration at a specific temperature ## Footnote It is a critical factor in the cement curing process.
36
What is the typical specific gravity of Ordinary Portland Cement (OPC)?
Around 3.15 ## Footnote This value can vary based on manufacturing materials.
37
What is Abrams' law?
The water-cement ratio influences all desirable qualities of concrete ## Footnote Reducing water weight improves strength and properties.
38
What is meant by the term 'water-cementitious materials ratio'?
The ratio of water weight to the total weight of cement and supplementary cementitious materials ## Footnote This term reflects modern concrete formulations.
39
What is the effect of excess water in concrete?
Causes development of capillary voids, increasing porosity and reducing strength ## Footnote Extra water is needed for workability but should be minimized.
40
What does plastic consistency indicate?
Condition where applied stress results in continuous deformation without rupture ## Footnote A plastic mixture has cohesion and flows without crumbling.
41
What does workability refer to in freshly mixed concrete?
Ease with which it can be mixed, placed, consolidated, and finished ## Footnote Workability determines the homogeneity of the concrete.

CMT (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions