Chapter 25 Flashcards
The voids in CMUs are called?
cells
The nominal length of typical CMU is?
16in.
The nominal height of typical CMU is
8in.
The nominal width of typical CMU is:
a. 18in.
b. 16in.
c. 12in.
d. 8in.
e. variable
e. variable
A typical CMU has:
a. one web
b. two web
c. three webs
d. four webs
e. five webs
c. three webs
A typical CMU has:
a. one face shell
b. two face shells
c. three face shells
d. four face shells
e. five face shells
d. four face shells
Which of the following CMU shapes is used to simulate a stack-bond wall, although the wall, in fact, made with a running-bond pattern?
a. Lintel
b. bullnose unit
c. sash unit
d. unit with projection face shells
e. scored unit
e. scored unit
Which of the following CMU shapes has a rounded corner?
a. lintel
b. bullnose unit
c. sash unit
d. unit with projecting face shells
b. bullnose unit
CMUs with projecting face shells can be used on both sides of a control joint in a wall. The other unit that is commonly used in the same situation is a:
a. scored unit
b. bullnose unit
c. sash unit
d. intel unit
c. sash unit
Which of the following CMU shapes has U-shaped profile in its vertical cross section?
a. Lintel unit
b. bullnose unit
c. Sash unit
d. Unit with projecting face shells
e. scored unit
a. Lintel unit
Arching action occurs in a masonry wall with:
a. a running-bond pattern
b. stack-bond pattern
c. both (a) and (b)
d. neither (a) nor (b)
a. a running-bond pattern
A lintel over an opening in all masonry walls is designed to carry the load from triangle-shaped superimposed masonry. True or False
False
If a CMU wall is vertically reinforced at 16in. on centers, which of the following units will you recommend for use in the wall?
a. A-unit
b. H-unit
c. Standard unit with three webs
d. sash unit
e. Bond beam unit
A. A-unit
If a CMU wall is vertically reinforced at 8in. on centers, which of the following units will you recommend for use in the wall?
a. A-unit
b. H-unit
c. Standard unit with three webs
d. Sash unit
e. Bond beam unit
b. H-unit
If a CMU wall is vertically reinforced at 24in. on centers, which of the following units will you recommend for use in the wall?
a. A-nit
b. H-unit
c. Standard unit with three webs
d. Both (a) and (b)
e. Both (a) and (c)
e. Both (a) and (c)
The center-to-center spacing of vertical reinforcement in a CMU wall cannot be less than 8in. True or False?
True
Which of the following CMUs has slotted webs that are broken before being laid in the wall?
a. A-unit
b. H-unit
c. Standard unit with three webs
d. Sash unit
e. Bond beam unit
e. Bond beam unit
The term pilaster and pier are synonymous. True or False?
False
A split-face CMU is made by treating a standard CMU with an oxyacetylene torch to produce a very smooth surface on one or more faces of the unit. True or false?
False
A burnished CMU is made by treating a standard CMU with an oxyacetylene torch to produce a very smooth surface on one or more faces of the unit. True or false
False
In a typical CMU wall, face-shell mortaring is used. This implies that the mortar is placed:
a. only on the horizontal surfaces of the face shells
b. on the horizontal and vertical surfaces of the face shells
c. on the horizontal surfaces of the face shells as well as the webs.
d. on the vertical surfaces of the face shells only.
b. on the horizontal and vertical surfaces of the face shells
The grouting of the cells of a CMU wall is required where:
a. the cells are provided with steel reinforcement
b. greater fire resistance of the wall is required
c. greater sound insulation of the wall is required
d. all of the above
e. both a and b
D. all of the above
Joint reinforcement refers to?
the horizontal reinforcement in a masonry wall
Joint reinforcement in CMU walls generally consists of:
a. single wire
b. two parallel wires connected together by cross wires
c. three parallel wires connected together by cross wires
d. two parallel wires without cross wires
e. none of the above
b. two parallel wires connected by cross wires
The primary purpose of joint reinforcement in a CMU wall is to?
e. absorb the tensile stress in the wall caused by the shrinkage of units
Bonds beams in a CMU wall can be used to serve the same purpose as joint reinforcement. True or False
True
The spacing of control jointing in a CMU wall:
a. should not exceed 25ft.
b. is function of the length-to-height ration of the wall
c. is a function of the average annual air temperature of the location
d. (b) and (c)
e. (a) and (b)
e. (a) and (b)
Masonry grout is mixture of:
a. Portland cement and water
b. Portland cement, aggregate, and water
c. Portland cement, lime, wand water
d. lime, aggregate, and water
e. none of the above
e. none of the above
Masonry grout has a slump of approximately:
a. 2 to 3 in.
b. 3 to 4 in.
c. 4 to 5 in.
d. 5 to 6 in.
e. none of the above
e. none of the above
Some architects and engineers prefer to specify low-lift grouting in masonry walls because:
a. it is more economical
b. it saves construction time and effort
c. it does not require the use of coarse aggregate
d. it does not require Portland cement
e. None of the above
e. None of the above
Geologically, the earliest rock on the Earth’s surface was?
an igneous rock
Marble is what kind of rock?
Metamorphic rock
Granite is what kind of rock?
an igneous rock
Slate is what kind of rock?
Metamorphic rock
Which of the following stones is generally more vulnerable to disintegration by an acidic atmosphere?
Marble
In general terms, which of the following stones is considered most durable?
a. Marble
b. Granite
c. Limestone
d. Sandstone
e. Slate
Granite
