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The flashcards below were created by user
Grace22fire
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Combined with smoke and fire observation, ISOs must apply a skill to predict
collapse potantial and collaspe zones.
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Three types of loads can be transmitted through a structual member:
Axial, Eccentric, and torsion loads
*impose loads and create forces on structure
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Basis of of all building construction technique is to carry
a load to the earth.
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direction or application of a load to a component is the______ of the load.
imposition
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Loads are applied to a structual member as
compression, tension, or shear forces.
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The mass (or_______) of a material directly impacts it fire resistance.
density
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_______ is heat resistance , and heat resistance is _____.
mass is heat resistance , and heat resistance is time
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In the past the fire service looked at the characteristics of four basic material types:
wood, steel, concrete, and masonary.
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Wood has a _______ resistance to forces compared to its weight,
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The more mass a a section of wood has, the more material must be burned away before its strength is lost. this true of what type of wood?
native woo, wood that has been cut from a tree.
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includes a host of products that consist of many pieces of native wood ( chips, veneers, and sawdust)glued together to make a sheet, a long beam, or a strong column.
Engineered wood
p91
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The glue that binds wood products together require only _____ to break down.
heat
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Is a mixture of carbon and iron ore heated and rolled into structural shapes to form elements for a building.
Steel
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popular choice for girders, lintels, cantilevered beams, and columns,
Steel
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type of steel?
like cable, bolts, rebar, and lightweight fastner, loses 55percent of its sterngth at 800 degrees Fahrenheit.
Cold drawn steel
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type of steel?
used for beams, and columns lose 50 percent if its strength 1,100 degrees Fahrenheit.
Extruded structual steel
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Structural steel _______ or _______ as temperture rise.
elongates or expands
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At _____ degrees Fahrenheit, a 100 foot long beam can elongate __ inches!
At 1,000 degrees Fahrenheit, a 100 foot long beam can elongate 10 inches!
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Why is cooling structual steel with fire streams just as important as attacking the fire?
- Steel softens, elogates, and sags when heated, leading to collapse.
- p91
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what type of material?
is a mixture of Portland cement, sand, gravel, and water that cure into a solid mass.
Concrete
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Concrete has excellent _______ strength when cured.
compressive strength
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The final strength of concrete depends on the ratio of these materials -especially the ratio of ______ to _______ _______.
water to Portland cement.
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Concrete has poor ______ and _____ strength, ____ is added as reinforcment.
tensile and shear strength, steel is added
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All concrete contains some _______ and continues to _____ _______ (humidty) as it ages.
moisture and continues to absorb moisture
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Concrete
When heated this moisture expands, causing the concret to _____ or ______.
crack or spall
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common term that refers to brick, concrete block, and stone .
'Masonary'
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Masonary is used to form ____ _____ walls because of its ________ strength, but it can be used to build a ______wall.
- load bearing wall
- compressive strength
- veneer wall.
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masonary units (block, brick, and stone) are held together using ______.
morter
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varied but usually contain mixture of lime, Portland cement, water, and sand.
have little to no tensile or shear strength, they rely on compressive forces
Morter mixes
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When taken individually these have excellent fire-resistive qualities. they are?
Brick, concrete block, and stone
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A _____ _____ that exceeds the compressive forces within a masonary wall causes quick collapse.
lateral force
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"composite" refers to a
combination of four basic materials, as well as various plastics, glues, and assembly materials.
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Lightweight wooden I beams (the slang termis "I joists") are a combination of two engineered wood products: .
laminated veneer lumber and orentated strand board.
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is created by using sheet veneers of wood (with the strand direction) the are glued and pressed together to form a piece of lumber.
Laminated veneer lumber (LVL)
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is sheeting created with wood chips ( the strands are orientated in mulitply directions) and an emulsified glue.
Orientated strand board (OSB)
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what are LVL and OSB used for in Light weight wooden I beams?
- LVL= top and bottom(tensile forces) chord
- OSB= web between the chords
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FiRP
fiber-reinforced plastic, usually pronounced "ferp"
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___ can mixed with wood to give it incredible tensile strength- with minimal mass.
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Structual elements can be described simply as
columns, beams, and connections used to assemble a building.
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if an element can no longer pefomed as designed, ______ takes over and pull the element to earth.
gravity
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vertical supports of buildings, even though they can be diagonal or even horitzontal.
Any structural component that tranmits a compressive force parallel theough its center is called
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The guiding principle that is column is totally in _______.
compression
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A structual element that delievers loads perpendicularly to its imposed load is called
a beam.
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something that supports a beam
column
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beams are used to create ?
a covered space
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Beams
subjected to to the ______ load on to itself and of anything placed on it. This load causes the beam to deflect, that is, the top of the beam is subjected to _____ and the bottom of the beam is subjected to ______.
- imposed load
- compressive force
- tension
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What dictates the amount of load a beam can carry or the distance a beam can span?
- the distance between the top of the beam and the bottom of the beam
- p94
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A few types of beams
- Simple beam
- Continuos beam
- Cantilever beam
- Girder
- Joist
- Truss
- Perlin
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A beam transfers a load _________ to the load, creating compressive and tensile forces within itself.
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Simple beam
Supported at the two points near it ends
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Continous Beam
supported in three or more places
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Cantilever beam
supported only at one end ( or beam that extends well past a support in such a way that the unsupported overhang places the top of the beam in tension and the bottom in compression)
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Lintel
Spans an opening in a load bearing masonary wall, such as over a garage door opening, (often called a "header" in slang)
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Supports other beams
Girder
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A wood framing memeber used to support floors or roof decking
( called a rafter when it is attached to a ridge board to form a peak)
Joist
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A series of triangles used to form a structual element to act as a beam( in many ways, a "fake" beam because it uses geometric shapes, lightweight materials, and assembly of components to transfer loads just like a beam)
Truss
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"weaklink" in a structual failure
Connections
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The important point of reagrding construction classifcation is not in the method choosen but in you ability to
look at a building and understand how the building is assembled and what materials were used.
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Five board categories of buildings/ classes
- type l- fire resistive
- typell-Noncumbustible
- typelll-ordinary
- typelV-Heavy timber
- typeV-Wood frame
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these five classifcations are _________ _________ for ISO and may lead to ______ assumptions about the makeup of a building.
- dangerously incomplete
- deadly
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Type l: fire- resistive
the structual elements are of an approved noncumbustible or limited combustible material with sufficient fire resistive ratings to with stand the effects of fire and prevent its spread.
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Concrete incased steel, monolithic-poured cement, and steel spray-on fire pretection coating are typical of
Type l
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which building class?
are large multistoried structures with the multiple exits.
diffcult to fight fire due to large size of the building and the subsequent high fire load.
Type l
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describe:
In Type ll (Noncombustible) construction, structual .......
elements do not qualify for Type l construction and of an approved non combustible or limited combustible material with sufficient fire- resistive rating to with stand the effects of fire and prevents it s spread from story to story.
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more often than not building in this type of construstion are steel. such as Modern warehouses, small arenas, and newr churches and schools.
Type ll Noncombustible
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Type ll building are susceptible to steel deformation and result in collapse. because...
Steel is not required to have signifcant fire-resistive coatings
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fire spread in Type ll is influenced by
the contents
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type of construction?
often misapplied to wood frame buildings
Type ll, "Ordinary"
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by definition ordinary constrution in cludes building in which the
load bearing walls are noncombustibleand the roof and floor assemblies are wood.
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Type lll is most prevalent in most ________ or "________" areas of established town and villages.
downtown or "main street" areas
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Most common Type lll, ordinary construction, is the
strip mall with masonary walls and light weight steel or wood trusses.
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In ordinary contruction, older building, numerous remodels, restorations and repairs have created
suspect wall stablility and hidden dangers.
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Ordinary construction p99
Decorative stars or ornaments ( called spreader) outside a brick wall mean
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defined as those have block or brick exterior load- bearing walls and interior structual members, roofs, floors, and arches of solid or laminated wood without concealed spaces.
Type lV Heavy timber
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Heavy timber
minimum demensions for structual wood is typically
over 8 inches.
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firefighters mistakenly call Type lV "_______".
- "mill construction"
- mill construction=more stout, may or maynot have block walls, is constructed without hidden voids
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Heavy timber fire spread can be
fast due to wide open areas and content exposure
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heavy timber
because of mass and large quantity of exposed structual wood , fires burn for
a long time
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why were heavy timber beams designed to release from walls?and how?
- to protect load bearing wall
- accomplished by making a fire cut on the beam, and is gravity fit into pocket within the exterior load-bearing masonary wall.
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type of construction?
most common type of construction; homes, newer small businesses, and even chain hotels are built primarly of wood.
Type V
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Older wood frame building were built as _______ _______, that is?
- ballon frame,
- wooden studs run from the foundation to the roof, and the floors are "hung" on the studs.
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TypeV
In the early 1950s, builders started using
platform framing, in which one floor is built as a platform fot the next floor.
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Newer wood framed structures utilize lightweight wood trusses for roofs and floors, this like a ________ ballon frame that can allow ______lateral fire spread.
- horizontal ballon frame
- quicker lateral
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TypeV
some codes require truss spaces to have fire stopping ___ _____feet.
500 square feet
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Wood frame structures appear like what other type of construstion because brick wall appearance.
appear like Type lll
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What is used to pretect structual members from fire in wood frame construction?
gypsum board( drywall or sheetrock)
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In newer wood frame buildings often the only warning that a fire has penetrated these spaces is the issuance of
smoke from crawl space vents, gable-end vents, and eaves.
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what should expect if a hybrid building is on fire?
Expect rapid collapse due to low-mass, high surface to mass exposure of structual elements!
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Lightweight steel
pg 102
"post and beam"
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ICF use expanded ______ (EPS) to form a concrete mold for ______.
- Insulated Concrete Forming (ICF)
- polystyrene(EPS)
- walls
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the two principles types for ICF
ICF blocks and ICF panel
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ICF block is mostly_____ and will likely melt from ______ of a fire.
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Expect ______collapse of ICF block.
rapid
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Structual insulated Panels(SIP) a construction method the uses panels made from ____ and ______ for load bearing walls and roofs;
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SIP
Panels are simply _____ sheet of OSB glued to ____ sides of a EPS sheet that is typically ____ to ____ inches thick
- two sheet of OSB
- both sides of EPS
- 6 to 8 inches thick
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SIP
extended window or door jambs may indicate
the wall is thicker than that of typical wood or masonary buildings.
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Building analysis during any incident should be _____, that is, performed on a ______ basis as conditions change and time goes by.
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Five step approach to predicting a collapse
- Step 1: classify the construction type
- Step 2: Dteremine structual involvment (read the smoke and flames)
- Step 3: Visualize the trace loads
- Step 4: Evaluate time
- Step 5: Predict and communicate collapse potential (foundation for zoning)
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Step 2
pg 105
determing whether a fire is a content or structual
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Dark or gray smoke venting under pressure from structual seems, ridge boards, eaves, and attic vents is significant indicator that
heat and likely fire are present in that space.
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unfinshed wood that is being rapidly heated emits what kind of smoke?
unfinshed wood/ heated rapidly=brownish smoke
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Step 3
pg 106
- "undressing" a building
- this step helps ISO define the weaklink
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Weak link that lead to collasp
pg106
- connections=most structual failure
- overloading= not designed for excessive loads/ remodeled
- occupancy switch=never intended use/ex. home-lawyer office
- Trusses="fake beams"
- Void spaces= (typelll)
- Stairs=new stairs fail quickly (glued)
- Parapet walls=little stability
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Gusset plate
- typically hold together trusses
- pop out quickly during rapid heating and fall off when small portion of the wood truss burns away- after as little as 5 mins
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Step 4: evaluating time
pg 107 -108
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Factors that accelerate potiential collapse and truisms
pg 108
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NIOSH recommendation in relation to trusses
Ensure firefighters performing firefighting operations under or above trusses are evacuated as soom as determined that the trusses are exposed to fire- not according to a time limit.
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Step 5
establishment of ?
collapse zone
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A collapse Zone is a more specific form of a ____-_____ zone.
- no-entry
- (no-entry zone for firefighters)
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suggests that collapse zone is at least ___times the height of the thing that is anticipated to fall.
1 1/2 times the height
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when its not possible or desirable to honor the 1 1/2 distance rule, a _______ approach can be considered when it absolutely neccessary to get closer.
flanking
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When flanking a collapse zone, firefighters should use ________ and have rapid _______ options communicated prior to the approach.
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Partial collapse
pg 109
the building can accept the failure of a single component and still retain some strength.
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general collapse
pg 109
New truss system
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an inward fall of a wall may cause the ______of the wall to kick out.
bottom
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"late signs"
- deterioration of morter joints and masonary
- signs of building repair, including reinforcing cables, and tie rods
- bulges and bowing of walls
- sagging of floors
- abandomned buildings with missing roof, wall, or floor segments
- Large volumes of fire impingingon structual components and spaces
- multiple fires on the same building or damage from previous fires
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________ operations should be the default for all ________ site fires.
- Defensive operations
- construction
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One of the important functions of an ISO is to offer
judgement about the collapse potential of building during incidents
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The five classic fire types of construction are being challenged by
new construction or "hybrid", methods
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Buildings under construction are "___" from a firefighting point of veiw; they collapse quickly
"Losers"
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Hoe does a masonary wal achieve strength?
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What type of visual warning signs would expect to see when the glued truss loses integrty?
Pg112
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Smoke leaving a structure has four key attributes
- volume
- velocity (pressure)
- density
- and color
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Smoke is best defined as the
products of imcomplete combustion that include as aggregate of solids, aerosols, and fire gases that are toxic, flammable, and volatile.
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solid suspended in a thermal plume include
carbon(soot and ash), dust, and airborne fibers.
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Smoke aerosols include
Whole host of hydrocarbons(oils and tar) and moisture.
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Complete combustion of common materials renders
heat, light, carbon dioxde, and water vapor.
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carbon monoxide (CO)
self ignition temp
flammable range in air
Flashpoint
pg117
- self ing.temp=1123 F,
- flammable range in air= 12-14%, below 300 F negligible
- flashpoint= none
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Acrolein (C3H4O)
self ignition temp.
flammable range in air
flashpoint
- self ignition temp= 450 F
- flammable range in air= 3-31%
- flashpoint= -15%
- -by product of incomplete combustion of wood, wood products and other cellusic materials.
- -polyethylene can also render acrolein.
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Benzene (C6H6)
self ignition temp
flammable range in air
flashpoint
- self ignition temp= 928 F
- flammable range in air= 1-8%
- flashpoint= 12 F
- -most plastics release benzene while burning.
- -Benzene is a common product of the burning of fuel oils.
- pg117
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hydrogen cyanide (HCN)
self-ignition temp
flammable range in air
flashpoint
- self ignition temp= 1,000 F
- flammable range in air= 5-40%
- flashpoint= 0 F
- -porducedwhen high temp break down nitrogen-containing products.
- -HCN is quite flammable and is considered extremely toxic.
- pg117
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two triggers may cause accumulated smoke to ignite:
- the right temperature
- the right mixture
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Smoke tells you how ______ the fire is about to become...
pg117
intense
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an event that can catch firefighter off guard and endanger them: flashover, backdraft, smoke explosion, and rapid fire spread.
Hostile fire event
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Hostile fire events: (warning signs)
flashover
Backdraft
smoke explosion
rapis fire spread
table 7-2*more note!
- flashover: turbulant smoke flow/rollover/autoignition temp
- backdraft: yellowish-gray smoke/bowing,black stained windows/signs of extreme heat on outside of box or compartment.
- smoke explosion: smoke that is being trapped above the fire/ signs of a growing fire/ signs of smoke starting
- to pressurize
- Rapid fire spread: increase in smoke speed/ smoke flowing from hallways and stairways faster than a firefighter can move.
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The ISO must take the proactive approah by watching the ______ _______ ________ and determining the ______, ______, and______ _______ of a fire in a building, as well as the likelihood of a _______ fire event.
The ISO must take the proactive approach by watching the four smoke attributes and determining the location, stage, and fire spread of a fire in a building, as well as the likelihood of a hostile fire event.
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Smoke volume sets the stage for
- understanding the amount of fuel that are off-gassing in a given space.
- pg119
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Velocity
"speed " at which smoke leaves a building
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velocity is an indicator of pressure that has built up in the building. Two things can cause pressure in a building:
- heat and smoke volume
- pg120
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a flashover is likely to occur if the smoke flow charcteristic is
- turbulent smoke flow
- aka "agitated", "boiling", or "angry"
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stable and smooth flow of smoke
indicates the building(or compartment) is still absorbing heat
laminar smoke flow
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The most important smoke observation is whether its flow is
turbulent or laminar.
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Comparing the velocity of smoke different opening (like resistive openings) of the building can help the fire officer determine the
- location of the fire.
- pg121
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Density tall you ____ ____ things are going to be. The density of smoke refers to its _______
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the thicker the smoke the more ________ the _______ or ____ ___ will be.
more spectacular the flashover or fire spread will be
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Smoke color tell the stage of ______ and ______ to the _______ of the fire
- heating
- points to the location
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when first heated all solid materials emit what color smoke?
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wood materials smoke change to what color smoke?
tan or brown
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Plastic smoke and painted or stained surfaaces emits what color smoke?
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the more black smoke you see the ______the smoke is
hotter
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black smoke that is high veloscity and very thin (low density) is ______-pushed.
- flamed
- means ventilated/ open flamming near by
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smoke color can tell you the ______to a fire.
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As smoke leaves a ignition fuel, it heats up othe rmaterials and the moisture from those objects can cause black smoke to turn gray or even white over ______.
distance
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Fast moving white smoke =
slow or lazy white smoke=
- fast=traveled some distance
- slow= most likely early-stage heating
- pg122
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brown smoke from structual spaces indicates that fire is
transitioning from a contents fire to a structual fire.
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Faster/ darker smoke is _______to the fire seat, where as slower and/or lighter smoke is _______ ______.
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when smoke appears uniform- that is, it the same color and velocity from multiple openings...-fire is in a ?
- concealed space or deep seated
- (pg128-combustible voids )
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Black fire can reach temp of ?
describe?
solution?
- 1,000 f
- ...
- solution Vent and cool!
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factors that can change the appearance of smoke
pg125
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every element of smoke of heavier than air, yet it rises due to?
heat
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humid climates keep plume?
tight
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wind effect on fire?
pg 125
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low lying smoke can indicate the fire is ____ bring controlled by the system.
pg 125
not
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Who is usually in the best position to tell whether the firefighting effort s are being successful?
ISO
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Three simple steps the ISO can refine and rapidly apply the principles
pg127
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Black smoke with push
close to the seat of the fire or superhot smoke capable of instant ignition
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White smoke with velocity
Heat-pushed smoke that has travled a distance or has had the carbon filtered (like smoke through a crack)
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Predicting fire behavior is founded on the understanding of the _______ and _________ properties of smoke as well as on the specific warning sign of impeding ______ evnets.
- physical and chemical
- hostile
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Dynamic factors
weather, container size, thremal layering, and firefighting efforts all in fluence the appearance and behavior of smoke.
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what can help change action plans or warn firefighters of hostile fire events and therefore prevent firefighter injuries and death.
Communicating smoke observations
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