Deck 24: Masonry Materials-I Mortar and Brick

Question 1

A wall made of Portland cement mortar (without lime)is more watertight than a wall made of Portland cement and lime mortar.

Answer 1

False

Question 2

Masonry mortar types are classified as

A)Types M, S, N, and O.
B)Types I, II, III, and IV.
C)Types 1, 2, 3, and 4.
D)Types P, Q, R, and S.
E)either B or C.

Answer 2

A

Question 3

Bricks that have core holes are

A)molded bricks.
B)extruded bricks.
C)A and B.

Answer 3

B

Question 4

A preblended cementitious mix for masonry mortar is available as

A)PCL cement.
B)mortar cement.
C)masonry cement.
D)A and B.
E)B and C.

Question 5

The mortar with the highest compressive strength is

A)Type 1.
B)Type P.
C)Type M.
D)Type I.

Question 6

Which of the following materials increases the mortar's compressive strength?

A)Portland cement
B)Mortar joint profile
C)Sand
D)Lime
E)All of the above

Question 7

For a masonry wall, the compressive strength of mortar should be as high as economically feasible.

Question 8

The term CMU is generally used as an acronym for

A)concrete masonry unit.
B)cement mortar underbed.
C)concrete masonry underbed.
D)clay masonry underbed.
E)clay masonry unit.

Question 9

Which of the following materials increases the mortar's workability?

A)Mortar joint profile
B)Lime
C)Portland cement
D)Sand
E)All of the above

Question 10

When mortar is specified using proportion specification, various solid materials that constitute masonry mortar are proportioned based on their

A)wet weights.
B)dry volumes.
C)wet volumes.
D)dry weights.
E)none of the above.

Question 11

The mortar most commonly used in an exterior masonry veneer wall is

A)Type I.
B)Type P.
C)Type S.
D)Type N.
E)Type II.

Question 12

Which of the following mortar joint profiles should be specified for an exterior wall?

A)Concave joint
B)Flush joint
C)Raked joint
D)Weathered joint
E)Struck joint

Question 13

Which of the following materials increases the mortar's cohesiveness?

A)Portland cement
B)Lime
C)Mortar joint profile
D)Sand
E)All of the above

Question 14

Bricks that have frogs are

A)molded bricks.
B)extruded bricks.
C)A and B.

Question 15

The flexural tensile bond strength of a masonry wall is a function of

A)the type of masonry units.
B)the quality of workmanship.
C)the compressive strength of mortar.
D)the curing of mortar.
E)all of the above.

Question 16

Mortar may be specified either by proportion specification or by property specification. Which of these two is more commonly used?

A)Property specification
B)Proportion specification

Question 17

The most commonly used mortar joint thickness is

A)1/2 in.
B)3/4 in.
C)3/8 in.
D)5/8 in.
E)1/4 in.

Question 18

The cementitious material(s)in contemporary masonry mortar consist(s)of

A)Portland cement.
B)lime.
C)Portland cement, lime, and sand.
D)Portland cement and lime.
E)Portland cement and sand.

Question 19

The mortar commonly recommended for use in masonry walls in seismic regions is

A)Type N.
B)Type I.
C)Type S.
D)Type II.
E)Type P.

Question 20

The flexural tensile bond strength of a masonry wall is relevant in

A)an unreinforced masonry wall subjected to gravity loads.
B)a reinforced masonry wall subjected to lateral loads.
C)an unreinforced masonry wall subjected to lateral loads.
D)a reinforced masonry wall subjected to gravity loads.
E)all of the above.

Question 21

In a running- bond wall,

A)each course consists of headers.
B)each course consists of stretchers.
C)each course consists of alternate headers and stretchers.
D)the courses alternate between headers and stretchers.
E)none of the above.

Question 22

A masonry unit that has 20% voids (e.g., 20% core hole area)is referred to as

A)a hollow unit.
B)a partially hollow unit.
C)a solid unit.
D)none of the above.

Question 23

The primary reason for providing core holes in bricks is to

A)increase the shear resistance of masonry walls.
B)reduce the weight of bricks.
C)provide uniform drying and firing of bricks.
D)none of the above.

Question 24

The freeze- thaw resistance of bricks has been found to be a function of the

A)compressive strength of bricks.
B)saturation coefficient (SC)of bricks.
C)boiling- water absorption of bricks.
D)all of the above.
E)A and B only.

Question 25

Efflorescence in masonry refers to

A)white spots in masonry walls.
B)excessive warpage of masonry units.
C)yellow spots in masonry walls.
D)excessive chippage of masonry units.
E)none of the above.

Question 26

In a Flemish- bond wall,

A)each course consists of headers.
B)each course consists of stretchers.
C)each course consists of alternate headers and stretchers.
D)the courses alternate between headers and stretchers.
E)none of the above.

Question 27

Bricks that are highly absorptive may need to be wetted before being laid in the wall.

Question 28

In specifying the dimensions of a masonry unit, which dimension is stated last?

A)Height, H, of the unit
B)Width, W, of the unit
C)Length, L, of the unit

Question 29

In specifying the dimensions of a masonry unit, which dimension is stated first?

A)Width, W, of the unit
B)Height, H, of the unit
C)Length, L, of the unit

Question 30

The weathering index (WI)of a location is a function of the

A)average annual winter rainfall of the location.
B)average annual freezing- cycle days.
C)average annual air temperature of the location.
D)all of the above.
E)A and B only.

Question 31

Retempering of mortar means

A)adding sand to mortar.
B)adding Portland cement to mortar.
C)adding water to mortar.
D)adding lime to mortar.

Question 32

Retempering of mortar, if needed, should be generally done within

A)1 h of the initial preparation of mortar.
B)4 h of the initial preparation of mortar.
C)2- 1/2 h of the initial preparation of mortar.
D)5- 1/2 h of the initial preparation of mortar.
E)none of the above.

Question 33

How is mason's sand different from regular sand?

Question 34

The nominal dimension of a masonry unit whose actual dimension equals 7- 5/8 in. is

A)7 in.
B)7- 1/2 in.
C)7- 3/4 in.
D)7- 1/4 in.
E)none of the above.

Question 35

What are the ingredients of masonry mortar?

Question 36

Masonry mortar consists of Portland cement, lime, sand, and water. Portland cement plus lime (PCL)and water function as the binder that binds the sand particles together. Which of the two-PCL or sand-is greater in quantity in masonry mortar and by how much?

Question 37

Per ASTM standards, facing bricks are classified as Types FBS, FBX, and FBA. Which of these types has the most stringent requirements for dimensional tolerance, chippage, and warpage?

A)FBX
B)FBA
C)FBS

Question 38

A masonry unit that has no voids (e.g., no core holes)is referred to as a

A)100% solid unit.
B)solid unit.
C)A or B.

Question 39

IRA is a measure of the tensile strength of a brick.

Question 40

In an English- bond wall,

A)each course consists of headers.
B)each course consists of stretchers.
C)each course consists of alternate headers and stretchers.
D)the courses alternate between headers and stretchers.
E)none of the above.

Question 41

Why is mortar color an important factor in the aesthetics of a masonry wall?

Question 42

Portland cement and lime (PCL)together function as the binder in masonry mortar. What is the role of lime (L)in mortar during construction?

Question 43

Portland cement and lime (PCL)together function as the binder in masonry mortar. What is the role of Portland cement (PC)in mortar after the wall has been constructed?

Question 44

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. What is this classification based on?

Question 45

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. The mortar can be specified based on the volume proportions of its three ingredients (Portland cement, lime, and sand)or based the mortar's strength. Which of the two specification methods-proportion specification or strength specification
-is commonly used?

Question 46

Why does spalling of masonry occur due to freeze- thaw action?

Question 47

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. The mortar can be specified based on the volume proportions of its three ingredients (Portland cement, lime, and sand)or based the mortar's strength. In which situations is strength specification used?

Question 48

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. Which of these types is recommended for use in non- load- bearing interior walls?

Question 49

What is the standard thickness of masonry mortar?

Question 50

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. Which is the strongest type and which is the weakest type?

Question 51

How can the spalling of masonry be prevented?

Question 52

Clay masonry units (often referred to as bricks)are manufactured either as extruded bricks or as molded bricks. Which type is more common in the United States?

Question 53

Portland cement and lime (PCL)together function as the binder in masonry mortar. What is the role of lime (L)in mortar after the wall has been constructed?

Question 54

ASTM specifications classify masonry mortar into four types. Name them.

Question 55

What is the approximate maximum temperature in the kiln in which the extruded bricks are fired?

Question 56

Why is concave mortar joint profile the most water- leakage resistant profile?

Question 57

Which mortar joint profile is typically used in exterior cladding walls and why?

Question 58

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. Which of these types is recommended for use in masonry foundation walls?

Question 59

Portland cement plus lime (PCL)and sand are three particulate materials in mortar. In this mix, sand is three times that of PCL. Is this 3:1 relationship by weights of the materials or by their volumes?

Question 60

ASTM specifications classify masonry mortar into Type M, Type S, Type N, and Type O. Which of these types is recommended for use in brick veneer cladding in a: (i)highly seismic region and (ii)nonseismic region?

Question 61

A brick has three dimensions: length, width, and height. In specifying the brick dimensions, which dimension is stated first, which next, and which is stated last?

Question 62

Explain why the masonry industry recommends the use of the weakest mortar that will give the required performance.

Question 63

A modular brick measures 4 × 2- 2/3 × 8. What are the dimensions of (i)rowlock face and (ii)soldier face?

Question 64

How can efflorescence on brick walls be removed?

Question 65

Give the ASTM classification of mortar types and their respective applications.

Question 66

What are the nominal dimensions of a modular brick?

Question 67

Explain the differences among the actual, nominal, and specified dimensions of masonry units.

Question 68

What does the initial rate of absorption (IRA)of a brick refer to? How does the IRA value affect brick wall construction?

Question 69

A modular brick measures 4 × 2- 2/3 × 8. What are the dimensions of: (i)stretcher face and (ii)header face of the brick?

Question 70

What is efflorescence in brick walls?

Question 71

What are the actual dimensions of a modular brick?

Question 72

Which properties of a brick determine its durability grade?

Question 73

What is a brick without core holes referred to in the masonry industry-as solid brick or core- less brick?

Question 74

In masonry industry, the masonry unit dimensions can be stated as actual dimensions or nominal dimensions. In which of these two types of dimensions are inch marks omitted?

Question 75

Describe the importance of Portland cement in mortar.

Question 76

Using sketches and notes, describe various commonly used mortar joint profiles. Which profile gives the most watertight wall and why?

Question 77

Facing bricks (FB)are made in two durability grades. Name the two grades with the more durable grade first. What does the durability of a brick refer to?

Question 78

The extruded bricks generally include holes. What are these holes called?

Question 79

Describe the importance of lime in mortar.

Question 80

Does efflorescence in a brick wall reduce the wall's strength?