Deck 21: Lime, Portland Cement, and Concrete

Question 1

Hydrated lime is available in two types, which are referred to as

A)Types X and Y lime.
B)Types A and B lime.
C)Types I and II lime.
D)Types 1 and 2 lime.
E)Types N and S lime.

Answer 1

E

Question 2

A pozzolanic material must be composed mainly of

A)microscopic silica.
B)amorphous silica and alumina.
C)microscopic and amorphous silica.
D)silica and alumina.
E)microscopic and crystalline silica.

Answer 2

C

Question 3

The main ingredient used in the manufacture of Portland cement is

A)limestone.
B)granite.
C)marble.
D)iron ore.
E)sand.

Answer 3

A

Question 4

Hydrated lime- water paste sets and hardens due to the

A)chemical reaction of water in lime with carbon dioxide in air.
B)chemical reaction of water with lime.
C)chemical reaction of oxygen in air with lime.
D)chemical reaction of nitrogen in air with lime.
E)chemical reaction of carbon dioxide in air with lime.

Question 5

A well- graded coarse aggregate is one in which the size of all aggregate particles is approximately the same.

Question 6

Quicklime is most commonly used in building construction.

Question 7

Quicklime reacts readily with water.

Question 8

Everything else being the same, a concrete with a larger coarse aggregate requires less Portland cement and water paste to give the same concrete strength.

Question 9

Hydrated lime is obtained by treating

A)slaked lime with water.
B)slaked lime with Portland cement.
C)limestone with water.
D)quicklime with Portland cement.
E)quicklime with water.

Question 10

The aggregate for concrete is generally subdivided into coarse aggregate and fine aggregate. The distinction between the two types of aggregate is based on the

A)aggregate's surface texture.
B)aggregate's particle size.
C)aggregate's parent rock.
D)aggregate's strength.
E)aggregate's density.

Question 11

The most commonly specified type of Portland cement is

A)Type II/III.
B)Type III.
C)Type C.
D)Type I/II.
E)Type pC1.

Question 12

One of the important cementitious ingredients in making Roman concrete was

A)clay.
B)volcanic ash.
C)Portland cement.
D)sand.
E)none of the above.

Question 13

The slump of concrete is measured

A)14 days after casting the concrete in a test specimen.
B)when the concrete is fresh.
C)1 day after casting the concrete in a test specimen.
D)28 days after casting the concrete in a test specimen.
E)7 days after casting the concrete in a test specimen.

Question 14

In a No. 4 sieve, the dimensions of voids are approximately

A)1 in. × 4 in.
B)4 in. × 1/4 in.
C)4 in. × 4 in.
D)2 in. × 2 in., giving an area of approximately 4.0 in.2.
E)none of the above.

Question 15

ASTM specifications classify Portland cement into five basic types, referred to as

A)Types X, Y, Z, p, and Q.
B)Types pC1, pC2, pC3, pC4, and pC5.
C)Types I, II, III, IV, and V.
D)Types A, B, C, D, and E.
E)none of the above.

Question 16

Which of the following materials is a pozzolana?

A)Concrete
B)Portland cement
C)Lime
D)Fly ash
E)Sand

Question 17

White Portland cement is generally weaker than normal (gray- colored)Portland cement.

Question 18

Lightweight structural concrete is heavier than insulating concrete.

Question 19

Lime is made by

A)mixing crushed limestone with nitric acid and then pulverizing the mixture.
B)heating crushed limestone and then pulverizing it.
C)mixing crushed limestone with water and then pulverizing the mixture.
D)mixing crushed limestone with sulfuric acid and then pulverizing the mixture.

Question 20

Which type of Portland cement is commonly used in making precast concrete members?

A)Type III
B)Type II/III
C)Type I/II
D)Type C
E)Type pC1

Question 21

In a high- rise building, the concrete may be brought from the ground to the location of placement by

A)chutes.
B)buckets.
C)pumping.
D)A or B.
E)B or C.

Question 22

What are the natural colors of quick lime and slaked lime?

Question 23

A #8 reinforcing bar has a diameter of

A)8 in.
B)1/8 in.
C)1 in.
D)none of the above.

Question 24

The rate at which concrete gains strength increases as the ambient air temperature increases.

Question 25

The compressive strength of concrete is generally measured

A)14 days after casting the concrete in a test specimen.
B)7 days after casting the concrete in a test specimen.
C)when the concrete is fresh.
D)1 day after casting the concrete in a test specimen.
E)28 days after casting the concrete in a test specimen.

Question 26

The test specimen used for determining the compressive strength of concrete in the United States is a

A)6- in.- diameter, 12- in.- high cone.
B)6- in.- diameter, 18- in.- high cylinder.
C)6- in.- diameter, 12- in.- high cylinder.
D)6- in.- diameter, 6- in.- high cylinder.

Question 27

High- strength concrete is defined as concrete whose compressive strength is greater than or equal to

A)4,000 psi.
B)8,000 psi.
C)5,000 psi.
D)10,000 psi.
E)6,000 psi.

Question 28

After concrete has been placed in the form, it should be consolidated as much as is economically practical.

Question 29

The slump of concrete is a measure of the

A)modulus of elasticity of concrete.
B)tensile strength of concrete.
C)compressive strength of concrete.
D)workability of concrete.

Question 30

How does lime mortar (mixture of lime + sand + water)set, harden, and gain strength?

Question 31

Give the chemical composition of limestone.

Question 32

Epoxy- coated bars are generally used in

A)high- rise buildings built in warm climates.
B)parking garages built in cold climates.
C)high- rise buildings built in cold climates.
D)parking garages built in warm climates.
E)none of the above.

Question 33

The consolidation of concrete on a construction site are generally done

A)manually using a 2- in.- diameter, 3- ft- long steel rod.
B)using a power- driven rod vibrator.
C)manually using a 1- in.- diameter, 3- ft- long steel rod.
D)using a power- driven plate vibrator.

Question 34

In a welded wire fabric mat that has a designation of 8 × 8- D4.0 × 4.0, the number 4.0 indicates that the wires are

A)deformed wires, each with a cross- sectional area of 0.4 in.2.
B)deformed wires, each with a diameter of 4.0 mil.
C)deformed wires, each with a cross- sectional area of 0.04 in.2.
D)deformed wires, each with a diameter of 0.04 in.
E)deformed wires, each with a cross- sectional area of 4.0 in.2.

Question 35

The heating of a substance at high temperature is called calcining. Which substances does the calcining of limestone produce?

Question 36

A high- strength concrete generally requires a

A)sand- reducing agent.
B)sand- increasing agent.
C)water- reducing agent.
D)water- increasing agent.

Question 37

Give the chemical composition of quick lime and slaked (hydrated)lime. Which of the two is used in building construction and why is the other not used?

Question 38

Steel reinforcing bars, generally used in concrete, have a yield strength of

A)120 ksi.
B)60 ksi.
C)80 ksi.
D)100 ksi.

Question 39

The finishing operations of a concrete surface usually involve striking, floating, and troweling. The sequence in which these three operations are generally performed is

A)striking, troweling, and floating.
B)troweling, floating, and striking.
C)striking, floating, and troweling.
D)floating, striking, and troweling.

Question 40

Portland cement sets and gains strength by virtue of its chemical reaction with

A)water.
B)carbon dioxide in air.
C)oxygen in air.
D)aggregates.
E)none of the above.

Question 41

What is a pozzolanic material, also called pozzolana?

Question 42

Explain how air- entrainment in concrete increases concrete's durability to freeze- thaw action.

Question 43

Which raw materials are used in the manufacturing of Portland cement (PC)?

Question 44

Explain where air- entrained concrete is required.

Question 45

In which situations is Type IV Portland cement (PC)used and why?

Question 46

Which pozzolanic material was used by the Romans to produce hydraulic cement for aqueducts-made of natural stone and mortar consisting of lime- sand mortar?

Question 47

What is the color of normal Portland cement (PC)and where is white PC used?

Question 48

Define: (i)concrete and (ii)concrete admixture.

Question 49

Explain the difference between air entrainment and air entrapment in concrete.

Question 50

List the uses of lime in contemporary construction.

Question 51

Explain what distinguishes fine aggregate from coarse aggregate.

Question 52

What does a pozzolanic material consist of?

Question 53

Portland cement (PC)is made in five types: Types I, II, III, IV, and V. Which of these is high- early strength PC and which is the general purpose PC?

Question 54

Name the pozzolanic material commonly used in contemporary construction. Where is it obtained from and in which situations is it used?

Question 55

What is Type V Portland cement (PC)and where is it used?

Question 56

Why is the setting and hardening of lime mortar a slow process?

Question 57

Name the types of hydrated lime and the differences between them. Which one is more commonly used and why?

Question 58

What is TypeI/II Portland cement (PC)?

Question 59

In which situations is Type III Portland cement (PC)used?

Question 60

Explain what hydraulic cement is. Give an example of hydraulic cement used in contemporary construction.

Question 61

How are concrete test cylinders generally cured in a concrete testing laboratory?

Question 62

What is hydration of Portland cement and why is it important?

Question 63

What is the maximum size of coarse aggregate (CA)in concrete.

Question 64

Which property of wet concrete are we generally interested in? How is it measured?

Question 65

What is meant by "well- graded" aggregate?

Question 66

Explain the difference between normal- weight (NW)and lightweight (LW)coarse aggregate.

Question 67

What is the minimum water- cement ratio for complete hydration of Portland cement?

Question 68

What is a No. 4 sieve? A No. 50 sieve?

Question 69

How is concrete cured at a construction site?

Question 70

From where and how is concrete transported to the construction site?

Question 71

After how many days of casting concrete in test cylinders, are they broken to determine the strength of concrete?

Question 72

What is concrete formwork?

Question 73

What is workability of concrete and how is it related to concrete's slump?

Question 74

Explain the difference between structural concrete and insulating concrete.

Question 75

What is water cement ratio (w- c ratio)and why is it important?

Question 76

What are the size and shape of the test specimen used in determining the strength of concrete?

Question 77

Which factors affect the slump of concrete?

Question 78

When concrete test specimens are broken to determine the strength of concrete, which type of strength are we measuring-compressive strength, tensile strength, bending strength, or shear strength?

Question 79

Explain the difference between normal- weight (NW)structural concrete and lightweight (LW)structural concrete.

Question 80

What is consolidation of concrete, why is it necessary, and how is it done?