Chapter 22

Question 1

According to building codes, plain concrete is not permitted in new construction. True or false?

Answer 1

False

Question 2

The term prestressed concrete refers to both pretensioned and postenstioned concrete. True or false?

Answer 2

True

Question 3

Which of the following is true?

a. The term strands includes tendons
b. the term tendons includes strands
c. none of the above

Answer 3

The term tendons includes strands

Question 4

Pretensioning is generally done at the precaster’s plant and yields a precast, prestressed concrete member. True or false?

Answer 4

True. Pretensioning is generally done at the precaster’s plant and yields a precast, prestressed concrete member.

Question 5

In a typical site-cast reinforced-concrete structure, the cost of formwork and shores is:

a. approximately equal to the combined cost of concrete and steel
b. approximately 75% of the combined cost of concrete and steel
c. approximately 50% of the combined cost of concrete and steel.

Answer 5

a. approximately equal to the combined cost of concrete and steel

Question 6

In site-cast concrete construction, shores are used in?

Answer 6

elevated concrete slabs

Question 7

High adjustability in shores made of dimension lumber:

a. is provided through lapped members together with specially made clamps
b. is provided through a screw-based metal assembly
c. is provided through a and b
d. is not provided.

Answer 7

C. is provided through a and b

Question 8

Scaffold type shores are generally made from what material?

Answer 8

Steel pipes

Question 9

High density overlay (HDO) on form plywood:

a. improves strippability of forms
b. allows easier cleaning of forms
c. increases reusability of forms
d. all of the above

Answer 9

d. all of the above

Question 10

Aluminum is commonly used as form and shore material because

Answer 10

its strength to weight ratio is high, which reduces the weight of forms and shores

Question 11

The term flying form refers to ?

Answer 11

a large formwork assembly for floor and roof slabs

Question 12

Reshoring concrete structures are necessary where excessive deflection of floor slabs or foundation settlement is anticipated on removal of shores. True or False?

Answer 12

False

Question 13

The structural design of formwork design is the responsibility of who?

Answer 13

The general contractor

Question 14

Form liners are used to?

Answer 14

produce textured concrete surfaces

Question 15

The primary purpose of steel reinforcement is to increase the tensile strength of concrete elements. However, steel reinforcement is also used to increase the shear strength and compressive strength of concrete elements. True or false?

Answer 15

True

Question 16

Stirrups are used in a concrete beam to?

Answer 16

to increase the shear strength of the beam beyond that provided by concrete

Question 17

Stirrups are generally made of No. ___ and No.___

Answer 17

No. 3 or No.4 bars

Question 18

A doubly reinforced beam is one in which

Answer 18

Reinforced bars are provided at the top and bottom of the beam

Question 19

Mechanical couplers are used where?

Answer 19

Where lap splicing of reinforcing bars will produce excessive congestion

Question 20

Hooks are used:

a. to lap splice reinforcing bars
b. where the lap-splice length is excessive
c. where lap splicing of bars will produce excessive congestion
d. all of the above
e. none of the above

Answer 20

None of the above

Question 21

Hooks in bars are produced by turning the bars through what degrees?

Answer 21

90 and 180

Question 22

Steel reinforcement in concrete elements that are permanently exposed to the earth, such as in footings, must have a minimum concrete cover of how many inches?

Answer 22

3in.

Question 23

The chairs used to support reinforcing steel bars are generally:

a. plastic chairs
b. steel-encased plastic chairs
c. steel chairs with plastic-coated feet
d. a and b
e. a and c

Answer 23

e. a and c

Question 24

The most important reason for providing ties in a concrete column is to?

Answer 24

Prevent the buckling of longitudinal column bars

Question 25

The most important reason for providing ties in a concrete wall is to:

a. prevent buckling of longitudinal bars in the wall
b. increase the compressive strength of the wall
c. increase the shear strength of the wall.
d. ties are generally not provided in a concrete wall

Answer 25

d. ties are generally not provided in a concrete wall

Question 26

Formwork for a concrete wall generally consist of?

Answer 26

Plywood with ties, walers, and stiffbacks fastened together with clamps

Question 27

A vapor retarder is required under?

Answer 27

some interior concrete slabs on ground

Question 28

The strength of concrete in a residential concrete slab on ground is generally what psi?

Answer 28

3,000psi

Question 29

A construction joint in a concrete slab on ground is required if the concrete slab cannot be placed in one continuous operation. True or false?

Answer 29

True

Question 30

The tendons used for prestressing a PT concrete slab on ground generally consists of what?

Answer 30

A single 1/2in diameter, 7 wire strand

Question 31

In a PT concrete slab on ground, the tendons are stressed from the ?

Answer 31

Live ends

Question 32

Pocket formers in a PT concrete slab on ground are used at

Answer 32

Live ends

Question 33

A PT concrete slab on ground may either be a ribbed slab or a constant thickness slab. true or false?

Answer 33

True