Ch. 8 Masonry and Ordinary Construction Flashcards
One drawback to the use of masonry is: _______________________.
Laying individual units hand by hand is labor intensive
The hardness of brick is dependent on ___________.
The soil used in its composition
Although masonry units are inherently resistant to _____, ______, and _____, deterioration of _______ often occurs over a __________.
Weather, fire and insects
- mortar
- long period of time
Bricks fired in a kiln:
@2,400F
40-150 hrs
Typical brick size is_________.
3 courses of brick plus mortar = _________.
3 5/8 in. by 7 5/8 in. by 2 1/2 in.
8 feet
Most common hollow concrete block size ________
8 x 8 x 16
3 types of concrete block/CMU’s
Hollow block
Solid block
Brick
Most common types of stone: (5)
Granite Limestone Sandstone Slate Marble
Stone laid in several ways:
- with or without mortar
- used as an exterior veneer attached by supports
Available in many textures and is architecturally popular for both interior PARTITIONS and exterior APPLICATIONS.
Glass block
Fired clay tile known as:
Structural terra cotta
Lower allowable stresses than those shown are used to take into account the ____________ and to __________.
- The mortar joint
- provide a factor of safety
Masonry units have _______________ strength.
No significant tensile
Allowable compressive strength of brick masonry would be:
250 psi
Masonry is __________ to fire.
Inherently resistive
Mortar also serves to ______________ of the masonry units permitting __________ transmission of the compressive load from unit to unit.
Mortar joints can be the ________________.
Cushion the rough surfaces
Uniform transmission
Weakest part of the wall
Mortar is available in ___ types and its compressive strength varies from as low as ______ to as high as ________.
5.
75 psi-2,500 psi
Most mortar is produced from a mixture of: (4)
- Portland cement (bonding agent)
- hydrated lime
- sand
- watert
Master streams during a fire can weaken mortar, either ______ or _______.
- from the PRESSURE of the stream
- from the FLUSHING EFFECT of the water
Most commonly encountered LOAD-bearing masonry walls are constructed from: (3)
Non-load bearing: (2)
Brick, Concrete block, Combination of brick and block.
Gypsum block, lightweight concrete block.
Nonreinforced masonry walls are USUALLY limited to a maximum height of:
AROUND 6 stories
When a building is to be more than __________ tall, the use of steel or concrete structural frame is usually more ECONOMICAL than erecting a nonreinforced masonry bearing wall.
Three or four stories
By using reinforced masonry, it is possible to construct load-bearing masonry walls to a height of _____ having a wall thickness of ________.
Ten stories or MORE
ONLY 12 inches
Masonry units laid side by side in a HORIZONTAL layer known as ________.
Course
Ways to provide/accomplish horizontal bond is:
- header course OR
- corrosion resistant metal ties
Horizontal courses of brick laid on top of each other in a VERTICAL layer known as a ______.
Wythe
When used as a supporting wall, thickness of masonry walls varies from a minimum of ________ to _________.
6 inches
Several feet
A brick wythe is commonly used in combination with a concrete block wythe. Such a design is referred to as a ________________.
Concrete block-brick faced (CBBF)
In the case of a cavity wall, metal ties are important because ________ is usually not practical.
Use of a brick header course
still horizontal but you see the ends of the bricks
Masonry walls are reinforced to __________ or to __________.
Permit a taller building OR
provide lateral stability against HORIZONTAL forces (seismic shock)
When bricks are placed end to end, they create a __________ course.
If bricks are placed vertically on end, a _______ course is created.
Stretcher
Soldier
One means of providing a HORIZONTAL BOND between the wythes is to place a course of ________ with the ends ______. A course of bricks laid in this matter is known as a _______.
- bricks across TWO wythes
- of the bricks FACING OUT
- HEADER course
Masonry walls can be reinforced by placing _____________ in a cavity between two adjacent wythes of brick wall.
________ can also be placed between the brick wythe and the concrete block wythe in a concrete-block-brick-faced wall.
Vertical steel rods (brick on brick) Tie rods (CBBF)
Reinforcement of masonry walls can include architectural features such as _____, ______, and _____.
Buttresses
Flying buttresses
Pilasters
Openings in masonry walls:
Openings pose a _____ problem because ________ between individual bricks or blocks provide __________.
- design
- the mortar joints
- little TENSILE support
- lintel, arch or corbelling*
Lintels frequently are:
Steel beams but can also be:
- reinforced concrete
- reinforced masonry
- wood, not in modern constr. because of shrinkage*
Lintel:
If height of the wall above the opening is _____ than the height of the ________ section, it is assumed lintel must support ________.
- shorter
- triangular
- the entire weight of masonry above the opening
Multistory buildings where large show windows are provided, the weight of TWO OR MORE floors of masonry walls is supported by:
Beam and column system at GRADE LEVEL
_______ is an extension of masonry or steel wall that projects above the roof. The purpose of a parapet on an exterior wall can be _______________.
Parapet
Architectural and functional
Artificial parapet made of:
EIFF
Exterior Insulation Finishing Foam
A parapet may also be required __________ to provide a barrier to the communication of fire between closely spaced buildings. Parapets project from ________ above the roof, usually without lateral support.
By a building code
1-3 ft or MORE
Parapets collapsed/dislodged/knocked over
- HIGH WIND, because of erosion/deterioration
- THRUSTS, because of collapse of roof
- AERIAL ladders extended/retracted, master streams
Ordinary construction is also known as __________.
Masonry, wood-joisted
p. 54 Exterior Protected
Wood-joisted masonry will have concealed combustible voids similar to:
Wood frame construction
Beam pocket is:
“Several inches deep”
metal strap as horizontal tie between masonry and end of beam
In ______ and _______, Wood joist/beams rest on masonry wall in an indentation known as ______.
Residential, small commercial bldgs
Beam pocket
End of joist or beam will be cut _________. This is known as a _______.
At a slight angle
Fire cut
Interiors of masonry buildings can be: (4)
Wood
Masonry columns/interior bldg walls
Cast iron (19th century)
Protected/unprotected steel w/masonry bearing walls
-therefore masonry walls could be fire resistive and non-fire resistive
When a beam transmits a large _____ load to a masonry wall, the wall may be increased in thickness at the POINT OF SUPPORT with a ______ to reduce the compressive stresses in the masonry.
Vertical
Pilaster
Multistory building with Masonry exterior walls with non-combustible protected interior framing members?
Masonry exterior walls with non-combustible unprotected interior framing members?
- Type I-A, I-B or II-B.
- Type II-B
Walls constructed with fire-rated concrete masonry units or bricks can have fire-resistance rating of _________.
2-4 or MORE
Massive masonry wall of _______ will have an INHERENTLY high degree of fire resistance.
18 inches or more in thickness
Steel tie rods:
- ______ to joists
- attached to ____ or ____ on outside
- presence of tie rods (does/does not) mean bldg undergone repairs
- bearing plates can be in the shape of _____.
- _____ occasionally placed for ornamental purposes.
- Parallel
- bearing plate or structural washers
- DOES NOT
- stars
- Stars
Greatest concern for FF’s when tie rods used to _______ rather than where they are part of the ______.
(Possible/not possible) to differentiate between repairs and original construction
- repair a wall, original construction.
- Usually possible (bearing plates)
Causes of masonry walls to deteriorate: (3)
Erosion of mortar - exposure to elements.
Shifting of foundation.
Wood rot - sagging of interior members
Bearing plates used for repairs:
____ with architecture of bldg.
____ positioned on wall.
Show other indications of repair such as _____
Less compatible
Not uniformly
Repairs to mortar joints
Masonry walls USUALLY collapse as a result of the ____________.
These horizontal forces create __________ at the inner face of the wall that the mortar cannot resist.
Collapse of interior wood framing
Tensile forces
Collapse zone BC p. 249
AT LEAST equal to the height
Strongest points in a masonry structure
Corners of the building
Other points of intersection
Stairwells or elevator shafts
These areas in masonry buildings can still create an exposure problem: (3)
Large windows
Unprotected soffits
Cantilivers in a fire-resistive wall
Decorative false front in masonry construction:
A false front can create:
Fascia
Combustible void
_____ is type of masonry construction in which exterior bearing walls are constructed of brick and interior structural framing of solid of laminated wood.
Mill construction (Commonly known as heavy timber)
2 characteristics that distinguish mill construction from Type III masonry construction:
Dimensions of wood structural members (larger)
Combustible concealed spaces are not permitted
Mill construction floors:
3 in. tongue and groove with 1 in. nominal tongue and groove flooring
Mill construction roofs:
Required to be 2 in. tongue and groove OR
1 1/8 structural panel or planks
Mill construction non-bearing partitions and walls:
Required to be NOT LESS than:
Two layers of 1 in. matched boards OR
Laminated construction 4 in. thick or 1-hr fire rated construction
Many structural components of mill not given fire resistance rating but instead:
Minimum dimensions
FF must be concerned with: (mill)
-integrity of timber connections under fire conditions
AND
-likelihood of collapse of roof and floor decks
Connections for mill:
Bolts
Special brackets
Bearing of one member directly on another
Oldest form of masonry is:
Ordinary with masonry bearing walls and interior wood framing
Building with masonry exterior can be:
Type I
Type II
Or
Type V
If masonry begins to _________, one way to stabilize is steel tie rods through masonry walls, parallel to joists.
Bulge or lean OUTWARD, to pull AWAY
