Chapter 5 - Reading Buildings Flashcards
______is nothing more than static and dynamic weights that are applied to buildings
loads
______is the weight of the building and anything permanently attached to it
dead load
____ refers to any force or weight, other than the building itself, that a building must carry or absorb
live load
5 ways a live load can be delivered to a building
concentrated distributed static suspended impact
loads cause stress and strain on a building and this is called _______
force
3 ways that a load can be imposed
axially
eccentrically
torsionally
axial load is imposed….
through the centroid of another object (something put a on a beam that is running vertically)
eccentric load is imposed….
off center to another object (like books on a wall shelf)
torsional load is imposed….
in a manner to cause another object to twist. (a side force pushing on the shelf)
3 types of force
compression (push)
tension (pull)
shear (perpendicular force)
4 characteristics of a building’s material
type (wood, steep, concrete)
shape
orientation (vertical/horizontal)
mass (density)
brittle vs. ductile
these are the 2 classifications on how materials will react when imposed to loads and resistance to forces.
brittle - material will fracture or fail
ductile - materials will bend, deflect, or stretch while retaining some strength
a _____ material will break before it bends
brittle
a _____ materials will bend before it breaks
ductile
Two types of wood used for building
native (cut from a tree)
engineered ( host of products that consist of many pieces of wood….like chips or sawdust)
_______ is a ductile material that has excellent tensile, shear, and compression strength
steel
a steel ____ is used for compression forces and shaped as a ___ or _____ and is typically oriented vertically
column
square, circle
a steel _____ will be shaped as an I when viewed and is typically oriented ______
beam
horizontally
Cold-drawn steel, such as cables, bolts, rebar, and lightweight fasteners loose 55% of its strength at _____ degrees
800
Extruded structural steel used for beams and columns loses 50% of its stregth at _____ degrees
1,100
structural steel _________ or ______ as temperatures rise
elongates, expands
cured concrete has excellent _______ strength
compressive
concrete has poor _________ and _____ strength
tensile, shear
______ is added to concrete for reinforcement
steel
_________ refers to the crumbling and loss of concrete material when exposed to heat.
spalling
concrete behavior when exposed to heat
it will slowly absorb and retain the heat
a _____ wall only supports its own weight and is commonly used as a decorative finish
veneer
a masonry wall relies on ____ imposed compression forces to keep it strong
axially (top to bottom)
if a wood roof that was on top of the wall burns away, the wall is weaker because the roof weight was compressing the masonry wall, making it stronger
a _____ is any structural element that transmits a compression force axially through its center
column
a _____ is a structural element that transfers loads perpendicularly to its imposed load
beam
the top of the beam is subject to ______ forces while the bottom is subject to _____ forces
compressive, tension
a _____ beam is supported at two points near its ends
simple
a ______ beam is supported in three or more places
continuous
a _____ beam is supported at only one end
cantilever (balcony)
a _____ beam spans an opening in a load bearing masonry wall
lintel (window or garage door opening)
a _____ is a beam that carries other beams
girder
a _____ is wood framing that support floors or roof sheeting
joist
a _____ is a series of triangles used to form an open-web structural element to act as a beam
truss
a _____ is a series of beams placed perpendicularly to other trusses or beams to help support roof decing
purlin
3 types of trusses
triangular (peaked roof construction)
parallel (flat roof)
arched (top is curved, bottom is straight)
connections are loaded in _____ force most of the time
shear
3 general types of connections
pinned
rigid
gravity
bolts, nails, and rivets are ______ type of connections
pinned
rebar in concrete, beaded welds, and adhesives are considered _____ connections
rigid
a beam sitting in a masonry wall pocket is a _____ connection
gravity
building era - 1700 - ww1
founder’s era
building era - ww1 - ww2
industrial era
building era - ww2 to roughly 1980
legacy
building era - 1980s to present
lightweight
Name that Era - Major fires present the threat of wall collapse
founders
Name that Era - most floor to wall connections use gravity
founders
Name that Era - lots of combustible voids
founders
Name that Era - major collapse threat from roofs
industrial
Name that Era - ballon framing
industrial
Name that Era - floors placed on a shelf (ribbon board)
industrial
Name that Era - curtain wall use
legacy
a _______ is a non-load-bearing wall that supports only itself and is used only to keep weather out
curtain wall
Name that Era - plywood replaced wood slats for flooring and roof decking
legacy
Name that Era - platform framing
legacy
a _____ is used to support walls that are collapsing outward
spreader
Name that Era - low mass structural elements
lightweight
Name that Era - high surface to mass ratio
lightweight
Name that Era - this era’s building collapse very quickly in fire conditions
lightweight
Name that Era - truss system, but it technically started in the 19__’s
lightweight, 60
Name that Era - prescription to perforance building
lightweight
order of building era’s - oldest to newest
founders
industrial
legacy
lightweight
order of building eras - newest to oldest
lightweight
legacy
industrial
founders
Name that Era - brought larger interior spaces for most buildings
legacy
Name that Era - drywall replaced lath and plaster
legacy
4 construction influences when sizing up a building
occupancy type
building era
building use
building size
To predict collapse, the ISO uses a classic ______ method
identity-analyze-decide
5 steps of the identity-analyze-decide
Step 1. Classify the building’s construction using the type/era/use/size approach.
■ Step 2. Determine structural involvement (read the smoke and flames).
■ Step 3. Visualize and trace loads.
■ Step 4. Evaluate time.
■ Step 5. Predict and communicate collapse potential (foundation for zoning).
Who can start a precautionary withdrawal?
the IC
what is A directive for crews to exit a building interior or roof in an orderly manner, bringing hoses and tools along.
precautionary withdrawal
what is A seemingly decorative star or other metal plate used to distribute force over more bricks or blocks as part of an unseen corrective measure that exists inside a building.
spreader
what type of load that is imposed in a manner that causes another object to twist.
torsional load
what is A beam that carries other beams.
girder
what is A load that is imposed off-center to another object.
eccentric load
what is A load that is imposed through the centroid of another object.
axial load
ive-step process that incorporates the identify–analyze–decide method of decision making:
- Identify the building classification using a type/era/use/size approach.
- Identify the fire and heat (smoke) locations, and determine whether structural elements are being attacked.
- Analyze the transference of loads that pass through the building and envision weak links.
- Analyze the passage of time and its impact on materials.
- Determine collapse potential and communicate warnings and collapse zones.
early or late? Indicators of collapse include sagging floors and roofs, cracks in masonry, settling noises, bulging or leaning walls, signs of construction or alteration, and large-volume fires attacking structural elements.
late
Collapse potential should be communicated using one of three options that are based on urgency are
emergency evacuation
precautionary withdrawal
planning awareness
Imposed loads create a resistive force in the materials they are acting on. The forces can be either ….
compression (crushing)
tension (pulling)
or shear (tearing).
The three ways loads are imposed are
axially (through the center)
eccentrically (off-center)
and torsionally (through twisting).
