Midterm Concrete Flashcards

1
Q

Which of the following techniques have proven successful in providing specified strengths in 4 hours of less? Select all that apply.

A

High Portland cement contents
Accelerating admixtures
Type III Portland cement

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2
Q

Air- en-training admixtures are primarily used to stabilize tiny air bubbles in concrete

A

True

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3
Q

Prebid and pre- construction conferences should be held to identify.

A

Lines of communication
Responsibilities
Discuss the contract requirements

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4
Q

“For all linear systems, the net response at a given place and time caused by two or more stimuli is
the sum of the responses which would have been caused by each stimulus individually”, is the:

A

Superposition Principle

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5
Q

Which deep foundation type is not suitable for installation in wet and/or loose soils?

A

Drilled piers

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6
Q

A hydraulic cement creates a chemical reaction when it comes in contact with water (hydration) but will not
cure under water.

A

False

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7
Q

(fill the blank) are the critical elements for a successful project regarding clearly delineated and
efficient office procedures for the administration of design, document control, checking of shop or
placing drawings, and processing design changes

A

Quality Insurance and Quality Control

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8
Q

Expansion joints are used at points of restraint, Expansion joints are used at points of restraint, including the junction between the elements of a structure. For example, they separate walls or columns from floors.

A

True

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9
Q

As part of jobsite preparation, before concrete is poured, it is important to be aware of any potential
increased pressure on the forms. Which of the following factors increase pressure on forms?

A

Increase in lift heights

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10
Q

Long term compressive strength of concrete using Type III Portland cement is higher than with
Type I Portland cement (general purpose).

A

False

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11
Q

Formwork accounts for 35 to 60% of the construction cost for concrete framed buildings.

A

True

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12
Q

Which of the following factors influence reinforcement development strength? I – Rebar spacing, II –
Concrete weight, III – Concrete cover, IV – Heat of hydration V – Rebar coating

A

I, II, III & V only

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13
Q

The temperature rise due to heat of hydration in concrete utilizing Type I Portland cement typically
levels off at approximately.

A

Between 3 and 7 days

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14
Q

Given the following design conditions for a Wall form system:
Concrete Mix = Type III cement without retarder, Concrete Unit Weight (w) = 150 pcf
Wall height (h) = 10 Feet high, Rate of Pour (R) = 8 Feet per hour,
Concrete Temperature (T) = 80 Degrees Fahrenheit,Wall Thickness = 12 inches
What is the maximum design pressure on the wall in pounds per square foot (psf)?

A

(1) (1) [150+43,400/80+2800(8/80)] =

972. 5

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15
Q

In regards to formwork, the lateral pressure on vertical forms is proportional to density and depth.

A

True

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16
Q

Given the following design conditions for a column form system:
Concrete Mix = Type III cement with retarder,Concrete Unit Weight (w) = 150 pcf
Column height (h) = 10, Feet highRate of Pour (R) = 8, Feet per hourConcrete Temperature (T) =
80 Degrees Fahrenheit
What is the maximum design pressure on the wall in pounds per square foot (psf)?

A

(1) (1.2) [ 150 + 9,000(8/80)] =

1260

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17
Q

Typically, the Design Professional should review and approve the concrete mixture proportions (mix
design) and submittals concerning materials, procedures, and testing data.

A

True

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18
Q

When installing concrete in extreme weather conditions, different techniques are used to help mitigate the
effect of temperature. Which of the following are typical cold weather concrete techniques? Select all that
apply.

A

Leave forms in place

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19
Q

Engineers apply factors to selected load cases to create Load Combinations used for design:

A

True

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20
Q

Contraction joints are where concrete placements stop and start.

A

False

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21
Q

Using the Strength Design Method, Design Strength must be _______ Required Strength.

A

Greater than or equal to

22
Q

Which of the following vertical loads on horizontal forms are considered “live loads”? Select all
that apply.

A

A. Workers

D. Walkways / Runways

23
Q

General purpose cement suitable for all uses except where special properties of the
other types are required.

A

Type I

24
Q

Cement used where moderate sulfate resistance is required, for drainage and
environmental structures in which sulfate concentration is higher than normal, or for
concrete exposed to seawater

A

Type II

25
Q

Cement used when high early strength is desired. Examples are early removal of
forms for cast-in-place concrete, precast concrete, and slipformed concrete. Under cold weather conditions.

A

Type III

26
Q

Cement used when the amount of heat of hydration must be minimized; for example,
in massive structures such as gravity dams, where thermal cracking is likely to occur

A

Type IV

27
Q

Cement used when high sulfate resistance is required, such as when concrete is
exposed to severe sulfate attack as with soils or groundwaters having a high sulfate
content

A

Type V

28
Q

Which of the following is not a Load Case used by Engineers in foundation design?

A

Flexible loads

29
Q

Which graphic shows the most appropriate rebar location for the load as shown in the figure
below?

A

B

30
Q

The slope of the linear portion of the stress-strain curve is called:

A

Modulus of elasticity

31
Q

When completing a concrete batch plant evaluation, it is important to check the “weights and
measures” seal on the scales, to make sure they are _______.

A

current

32
Q

Which party is responsible for the design of the concrete formwork?

A

Field Engineer

33
Q

Increasing the depth of a beam contributes significantly to _______ stress and _______ deflection.

A

reducing / limiting

34
Q

The maximum lateral pressure of concrete in psf (lb/ft2) on forms varies by the rate of placement, ft/hr.

A

True

35
Q

Which of the below variables has the greatest impact when calculating wind loads?

A

Wind speed

36
Q

The Engineering Design Team is usually led by the:

A

Project Manager

37
Q

As concrete hardens, lateral pressure on the forms decreases

A

True

38
Q

“A pictorial device used to analyze the forces and moments acting on a body”, is a

A

Free-Body Diagram

39
Q

Using a power buggy is a highly effective and practical method when placing a high volume of
concrete

A

False

40
Q

Beam A-B is subject to what forces?

A

Moment about the z-axis, torsion about the x-axis and shear along y only.

41
Q

Which of the following deep foundation types will require a specialty contractor for installation?

A

Driven piles

Auger-cast piles

42
Q

All foundations may be classified as one of two types:

A

Shallow and Deep

43
Q

Flexural strain at the neutral axis of a beam is

A

Zero

44
Q

Portland cement is a type of fly ash cement.

A

False

45
Q

Typically, review and approval of detailed formwork design is the responsibility of the Design
Professional

A

False

46
Q

When performing a concrete batch plant evaluation it is important to obtain a sample batch ticket.
Which of the following items should be found on the batch ticket? Select all that apply.

A

A. Batch time and date
B. Moisture content of aggregate
C. Water/Cement (w/c)

47
Q

Concrete strength development depends on which of the following? Select all that apply.

A

A. Curing temperature
C. Water-cement ratio
D. Chemical or mineral admixtures

48
Q

When performing a concrete batch plant evaluation it is necessary to determine the batch plants rate of
production (CY/hr) and estimated delivery rate to the project site (CY/hr).

A

True

49
Q

Which of the following best describes the costs associated with industrialized formwork?

A

High initial fabrication cost, but low cost per use

50
Q

Define Torsion:

A

Bending about a longitudinal axis

51
Q

All concrete that will be exposed to freezing weather during placement or in service should be air-entrained.

A

False