Deck 28: Exterior Wall Cladding-II Masonry, Precast Concrete, and Gfrc

Question 1

The most efficient weep hole in a brick veneer consists of

A)an open- head joint.
B)a plastic tube.
C)a wick.
D)none of the above.

Answer 1

A

Question 2

A mortar- capturing device in a brick veneer assembly is used

A)immediately below a flashing.
B)immediately above a flashing.
C)2 in. above a flashing.
D)at each floor level.
E)at each alternate floor level.

Answer 2

B

Question 3

In a brick veneer assembly with punched windows, vertical expansion joints should be provided at a maximum distance of

A)30 ft in the field of the wall and 30 ft from a wall's corner.
B)20 ft in the field of the wall and 10 ft from a wall's corner.
C)30 ft in the field of the wall and 20 ft from a wall's corner.
D)40 ft in the field of the wall and 40 ft from a wall's corner.

Answer 3

B

Question 4

When lintel angles and shelf angles are combined in the same angle in a brick veneer- clad building, the angle should be treated as a

A)lintel angle loose- laid over underlying veneer.
B)shelf angle anchored to the structural frame of the building.
C)lintel angle anchored to the structural frame of the building.
D)shelf angle loose- laid over underlying veneer.

Question 5

In a brick veneer wall assembly, the wind loads are transferred directly from the veneer to the building's structure.

Question 6

A lintel angle must be anchored to the building's structural frame.

Question 7

In a multistory building, shelf angles are typically used at

A)at the foundation level.
B)each floor level and at mid-height between floors.
C)each floor level.
D)all of the above.
E)A and C.

Question 8

For a brick veneer that bears on the foundation and continues to the top of the building without any intermediate bearing support, the maximum veneer height is limited to

A)20 ft.
B)40 ft.
C)35 ft.
D)30 ft.
E)25 ft.

Question 9

The anchors used to anchor the brick veneer to the backup wall are generally two- piece anchors to allow differential movement between the veneer and the backup

A)within the plane of the veneer.
B)perpendicular to the plane of the veneer.
C)in all three principal directions.
D)none of the above.

Question 10

A typical anchor used with a brick veneer and CMU backup wall assembly consists of a

A)two- piece anchor, of which one is an integral part of the joint reinforcement in the CMU backup wall and the other is embedded in the veneer's mortar joint.
B)three- piece anchor, of which two are fastened to the CMU backup wall and the other is embedded in the veneer's mortar joint.
C)two- piece anchor, of which one is embedded in the CMU backup wall and the other is embedded in the veneer's mortar joint.
D)A and B.
E)A and C.

Question 11

A shelf angle in a brick veneer assembly must provide

A)gravity load support to the veneer.
B)gravity load support to both veneer and backup.
C)lateral load support to the veneer.
D)lateral load support to both veneer and backup.

Question 12

A shelf angle must be anchored to the building's structural frame.

Question 13

The minimum width of the air space generally used between a brick veneer and a wood stud backup wall is

A)1 in.
B)1- 1/2 in.
C)2 in.
D)2- 1/2 in.
E)3 in.

Question 14

In a brick veneer assembly, flashing is required

A)at the foundation level.
B)under a window sill.
C)over a lintel angle.
D)over a shelf angle.
E)all of the above.

Question 15

The minimum required width of the air space between a brick veneer and a CMU backup wall is

A)1 in.
B)1- 1/2 in.
C)2 in.
D)3 in.
E)none of the above.

Question 16

A steel angle used to support the weight of a brick veneer over an opening is called a

A)relieving angle.
B)lintel angle.
C)shelf angle.
D)all of the above.
E)A or B.

Question 17

The backup wall in a brick veneer wall assembly consists of

A)a CMU wall.
B)a reinforced- concrete wall.
C)a wood or steel stud wall.
D)all of the above.
E)B and C only.

Question 18

The anchors in a brick veneer wall assembly provide

A)gravity load support to both veneer and backup.
B)gravity load support to the veneer.
C)lateral load support to the veneer.
D)lateral load support to both veneer and backup.

Question 19

In general, a CMU- backed brick veneer is more forgiving of construction and workmanship deficiencies than a steel stud- backed brick veneer.

Question 20

In a brick veneer assembly, weep holes are required

A)immediately above the flashing.
B)at each alternate floor level.
C)at each floor level.
D)2 in. above a flashing.
E)immediately below the flashing.

Question 21

In a brick veneer assembly with a steel stud backup wall, the design of studs is generally governed by

A)the deflection of studs to withstand lateral loads.
B)the shortening of studs to withstand gravity loads.
C)the compressive strength of studs to withstand gravity loads.
D)the bending strength of studs to withstand lateral loads.
E)any one of the above, depending on the wall.

Question 22

The GFRC skin is typically

A)1 in. to 2 in. thick.
B)1/2 in. to 3/4 in. thick.
C)2 in. to 3 in. thick.
D)1- 1/2 in. to 2- 1/2 in. thick.
E)none of the above.

Question 23

A GFRC curtain wall panel consists of

A)a cold- formed steel frame.
B)a GFRC skin.
C)anchors.
D)all of the above.
E)A and B.

Question 24

The glass fibers used in the GFRC skin are referred to as AR fibers. The term AR is an acronym for

A)alkali resistant.
B)alumina resistant.
C)acid resistant.
D)aluminum reinforced.
E)none of the above.

Question 25

The bricks used in brick- faced concrete curtain wall panels are generally

A)of the same thickness as those used in brick veneer construction.
B)thinner than those used in brick veneer construction.
C)thicker than those used in brick veneer construction.
D)any one of the above, depending on the building.

Question 26

The GFRC skin is obtained by

A)applying the mix with a trowel.
B)casting the GFRC mix in a mold similar to casting a precast concrete member.
C)spraying the mix over a mold.
D)any of the above, depending on the panel fabricator.

Question 27

The structural design of precast concrete curtain wall panels is generally the responsibility of the

A)structural engineer, who designs the structural frame of the building in which the panels are to be used.
B)structural engineer retained by the general contractor of the building.
C)structural engineer specially retained by the owner.
D)structural engineer retained by the panel fabricator.
E)none of the above.

Question 28

The anchors used in GFRC panels are typically

A)two- piece anchors.
B)one- piece anchors.
C)either A or B, depending on the thickness of the GFRC skin.
D)either A or B, depending on the lateral loads to which the panel is subjected.
E)none of the above.

Question 29

GFRC curtain wall panels are generally lighter than the corresponding precast concrete curtain wall panels.

Question 30

The veneer in a brick veneer wall is anchored to the backup wall with steel anchors, also called ties. What is the structural function of anchors and to which types of stress are they subjected?

Question 31

Precast concrete curtain wall panels are generally

A)cast on the construction site.
B)fabricated by a ready- mix concrete plant and transported to the construction site.
C)A or B.
D)none of the above.

Question 32

During the erection of precast concrete curtain wall panels, the panels are leveled. The leveling of the panels is provided in the

A)panels' tieback connections.
B)panels' bearing supports.
C)A or B.
D)A and B.

Question 33

Is a brick- veneer wall an anchored- veneer wall or an adhered- veneer wall?

Question 34

The strength of concrete used in precast concrete curtain walls is generally

A)greater than or equal to 5,000 psi.
B)greater than or equal to 3,000 psi.
C)greater than or equal to 4,000 psi.
D)none of the above.

Question 35

A masonry veneer, such as a brick veneer or CMU veneer, must be provided with a backup wall. Name commonly used alternatives for the backup wall.

Question 36

What is the typical thickness of brick veneer in a brick- veneer wall?

Question 37

The term GFRC is an acronym for

A)glass fiber- restrained concrete.
B)glass fiber- restrained cement.
C)glass fiber- reinforced concrete.
D)glass fiber- reinforced cement.
E)none of the above.

Question 38

The connection between the natural stone facing and the backup concrete in a stone- faced precast concrete curtain wall panel is obtained by

A)the roughness of the stone surface that is in contact with the concrete.
B)flexible steel dowels.
C)nonmoving steel dowels.
D)any one of the above.

Question 39

A bond break such as a polyethylene sheet membrane is generally used between the concrete and bricks in a brick- faced precast concrete curtain wall panel.

Question 40

The number of bearing supports in a precast concrete curtain wall panel must be

A)one.
B)two.
C)three.
D)four.
E)between three and six.

Question 41

How is dead load support provided to brick veneer in a multistory building?

Question 42

In a brick veneer wall assembly, the brick veneer over a wall opening is supported on a galvanized steel lintel angle, which rests on wall segments on either side of the opening. To which element in the assembly is the lintel angle anchored?

Question 43

A shelf angle in a brick veneer wall assembly is required to be discontinuous with a 3/8 in. gap between individual lengths, not exceeding 20 ft. Why is that so?

Question 44

The maximum distance permitted by the code between the inside face of the veneer and the outside face of the backup is 4- 1/2 in. With this restriction, what is the maximum thickness of insulation that can be used in the space between the veneer and the backup and why?

Question 45

Are the weep holes in brick veneer walls provided by drilling holes in bricks or by some other means? Explain and also give the center to center spacing of weep holes.

Question 46

What is the purpose of an air space between the veneer and the backup in a brick veneer wall assembly?

Question 47

The maximum distance permitted by the code between the inside face of the veneer and the outside face of the backup in a brick veneer wall assembly is 4- 1/2 in. What is this provision based on?

Question 48

What is a mortar- capturing device and where is it provided?

Question 49

What is flashing and where is it used in a brick veneer wall assembly?

Question 50

Which structural element provides dead load support for a shelf angle in a brick veneer wall assembly? Is the shelf angle placed on top of the support or is it anchored to its face?

Question 51

The anchors in a brick veneer wall assembly transfer the lateral load on the veneer to the backup. What is the dead load of the veneer supported on for a building whose height is 25 ft?

Question 52

What is the maximum height of brick veneer that can be supported on wall foundation without requiring any intermediate bearing support?

Question 53

What is the required width of air space between the veneer and the backup?

Question 54

In a brick veneer wall assembly, how wide is the gap between the shelf angle and the brick veneer below the shelf angle?

Question 55

Explain what a brick ledge is and its function.

Question 56

Because the veneer and backup in a brick veneer assembly are made of different materials and are exposed to different temperature variations, they expand and contract at different rates in their own vertical planes. Therefore, the anchors that connect the veneer to the backup should allow these movements to be unrestricted. Can this requirement be met by using one- piece anchors? If not explain, why not?

Question 57

Because the veneer and backup in a brick veneer assembly are made of different materials and are exposed to different temperature variations, they expand and contract at different rates in their own vertical planes. To allow the veneer and backup to move unrestricted in their own planes, the veneer anchors must be made of two pieces. However, one- piece veneer anchors are used in some situations. Which are those situations, and what does a one- piece anchor consist of?

Question 58

The first course of bricks laid on a shelf angle or lintel angle in a brick veneer wall are not laid on a bed of mortar. Why? Are the head joints mortared in the first course?

Question 59

The dead load support for brick veneer in a multistory building is typically provided through galvanized steel shelf angles at every elevated floor. The code permits the first 30 ft height of the veneer to be supported on wall foundation. Can the first one or two shelf angles below 30 ft height be eliminated? Explain.

Question 60

What is the maximum center- to- center spacing of brick veneer anchors?

Question 61

A brick veneer wall is provided with continuous vertical joints. What are their width and their purpose?

Question 62

The architectural design of PCC walls (exterior surface finish including any relief, color, aesthetic joints, etc.)is done by the architect in consultation with the precaster. The structural design of PCC walls is done by the precaster with information provided by the project's structural engineer. Name two important items of information that the precaster needs from the structural engineer.

Question 63

What is the disadvantage of cold- formed steel (CFS)stud backup for brick veneer as compared with CMU backup?

Question 64

In a brick veneer and cold- formed steel (CFS)backup wall assembly, where is the air- weather barrier (AWB)located? Is the AWB a sheet membrane or liquid- applied film? Explain.

Question 65

In a brick veneer and CMU backup wall assembly, where is the air- weather barrier (AWB)located? Is the AWB a sheet membrane or liquid- applied film? Explain.

Question 66

Is precast concrete curtain (PCC)wall used with frame structures, load- bearing wall structures, or both?

Question 67

Precast concrete curtain (PCC)wall panels are non- load- bearing elements. Yet the concrete used in them is of higher strength (generally 5,000 psi)than that used in the structural frame of the building (general 4,000 psi). Explain why that is so.

Question 68

Are the ties in a brick veneer wall with CMU backup integral with the horizontal joint reinforcement in CMU wall? Explain.

Question 69

In which building types is the precast concrete curtain wall system commonly used?

Question 70

Is the thickness of precast concrete curtain wall panels determined by lateral load considerations, or some other factors? Explain.

Question 71

What is the advantage of cold- formed steel (CFS)stud backup for brick veneer as compared with a CMU backup?

Question 72

Before the energy code requirement for continuous insulation came in force, the shelf angles for brick veneer support were anchored directly to the spandrel beam in a frame structure and the insulation was provided toward the outside of the shelf angle. With the requirement for continuous insulation, the insulation is sandwiched between the shelf angle and the spandrel beam. How then is the shelf anchored to the spandrel beam?

Question 73

A precast concrete curtain (PCC)wall panel is provided with two types of connections with the structural frame of the building. Name the two connection types.

Question 74

What is the typical thickness of CMU wall used as a backup for brick veneer in a reinforced concrete frame structure? Is this wall designed as a load- bearing or a non- load- bearing wall?

Question 75

How many bearing supports is a precast concrete curtain (PCC)wall panel provided with and where are they located?

Question 76

Precast concrete curtain (PCC)wall system competes with brick veneer system for cladding the buildings. Name two advantages of PCC wall system over brick veneer wall system.

Question 77

A brick veneer wall assembly must have a backup wall and so must a precast concrete curtain (PCC)wall. What is the difference between the two backup walls?

Question 78

Precast concrete curtain (PCC)wall system competes with brick veneer system for cladding the buildings. Name two disadvantages of PCC wall system over brick veneer wall system.

Question 79

Are the continuous vertical joints in brick veneer walls spaced at same spacing throughout the wall? Explain.

Question 80

The Brick Industry Association (BIA)recommends that the deflection in brick veneer backed by cold- formed steel (CFS)stud wall should not exceed L/600 for the lateral load on the wall, where L = stud span. What is the maximum allowable deflection if the height of studs is 10 ft?