Chapter 24 Masonry Materials-I (Mortar and Brick)

Which of the following mortar joint profiles should be specified for an exterior wall? a. concave joint b. raked joint c. flush joint d. weathered joint e. struck joint

a. concave joint

Bricks that have core holes are a. extruded bricks b. molded bricks c. (a) and (b)

a. extruded bricks

In specifying the dimensions of a masonry unit, which dimension is stated last? a. length, L, of the unit b. height, H, of the unit c. width, W, of the unit

a. length, L, of the unit

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

a. proportion specification

A masonry unit that has 20% voids (e.g., 20% core hole area) is referred to as a a. solid unit b. hollow unit c. partially hollow unit d. none of the above

a. solid unit

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

a. true

The mortar with the highest compressive strength is a. type M b. type I c. type 1 d. type P

a. type M

Masonry mortar types are classified as a. type 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)

a. type M, S, N, and O

A masonry unit that has no voids (e.g., no core holes) is referred to as a a. solid unit b. 100% solid unit c. (a) or (b)

b. 100% solid unit

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. FBS b. FBX c. FBA

b. FBX

The flexural tensile bond strength of a masonry wall is relevant in a. an unreinforced masonry wall subjected to gravity loads b. an unreinforced masonry wall subjected to lateral loads c. a reinforced masonry wall subjected to gravity loads d. a reinforced masonry wall subjected to lateral loads e. all of the above

b. an unreinforced masonry wall subjected to lateral loads

The term CMU is generally used as an acronym for a. clay masonry unit b. concrete masonry unit c. clay masonry underbed d. concrete masonry underbed e. cement mortar underbed

b. concrete masonry unit

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

b. each course consists of stretchers

T/F: A wall made of portland cement mortar (without lime) is more watertight than a wall made of portland cement and lime mortar.

b. false

T/F: IRA is a measure of the tensile strength of a brick.

b. false

T/F: for a masonry wall, the compressive strength of mortar should be as high as economically feasible

b. false

Bricks that have frogs are a. extruded bricks b. molded bricks c. (a) and (b)

b. molded bricks

Which of the following materials increases the mortar's compressive strength? a. mortar joint profile b. portland cement c. sand d. lime e. all of the above

b. portland cement

The primary reason for providing core holes in bricks is to a. reduce the weight of bricks b. provide uniform drying and firing of bricks c. increase the shear resistance of masonry walls d. none of the above

b. provide uniform drying and firing of bricks

The mortar most commonly used in an exterior masonry veneer a. type S b. type N c. type I d. type II e. type P

b. type N

Retempering of mortar, if needed, should be generally done within a. 5 1/2 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. 1 h of the initial preparation of mortar e. none of the above

c. 2 1/2 h of the initial preparation of mortar

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

c. each course consists of alternate headers and stretchers

Efflorescence in masonry refers to a. excessive chippage of masonry units b. excessive warpage of masonry units c. white spots in masonry walls d. yellow spots in masonry walls e. none of the above

c. white spots in masonry walls

In specifying the dimensions of a masonry unit, which dimension is stated first? a. length, L, of the unit b. height, H, of the unit c. width, W, of the unit

c. width, W, of the unit

The most commonly used mortar joint thickness is a. 3/4 in. b. 5/8 in. c. 1/2 in. d. 3/8 in. e. 1/4 in.

d. 3/8 in.

Retempering of mortar means a. adding portland cement to mortar b. adding lime to mortar c. adding sand to mortar d. adding water to mortar

d. adding water to mortar

The freeze-thaw resistance of bricks has been found to be a function of the a. compressive strength of bricks b. boiling-water absorption of bricks c. saturation coefficient (SC) of bricks d. all of the above e. (a) and (b)

d. all of the above

When mortar is specified using proportion specification, various solid materials that constitute masonry mortar are proportioned based on their a. wet weights b. dry weights c. wet volumes d. dry volumes e. none of the above

d. dry volumes

Which of the following materials increases the mortar's cohesiveness? a. mortar joint profile b. portland cement c. sand d. lime e. all of the above

d. lime

Which of the following materials increases the mortar's workability? a. mortar joint profile b. portland cement c. sand d. lime e. all of the above

d. lime

The cementitious material(s) in contemporary mortar consist(s) of a. portland cement b. lime c. portland cement and sand d. portland cement and lime e. portland cement, lime, and sand

d. portland cement and lime

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

d. the courses alternate between headers and stretchers

The mortar most commonly recommended for use in masonry walls in seismic regions is a. type I b. type II c. type P d. type S e. type N

d. type S

The weathering index (WI) of a location is a function of the a. average annual freezing-cycle days b. average annual winter rainfall of the location c. average annual air temperature of the location d. all of the above e. (a) and (b)

e. (a) and (b)

A preblended cementitious mix for masonry mortar is available as a. PCL cement b. masonry cement c. mortar cement d. (a) and (b) e. (b) and (c)

e. (b) and (c)

The flexural tensile bond strength of a masonry wall is a function of a. the compressive strength of mortar b. the type of masonry units c. the quality of workmanship d. the curing of mortar e. all of the above

e. all of the above

The nominal dimension of a masonry unit whose actual dimension equals 7 5/8 in. is a. 7 in. b. 7 1/4 in. c. 7 1/2 in. d. 7 3/4 in. e. none of the above

e. none of the above