Brannigan's Building Construction for the Fire Service 5th edition Flashcards
Number of firefighters killed in 2012 from collapse, falling through floors, running out of air, enveloped by explosion, or struck by falling debris
9
m’aider
Mayday
Considered a policing function
Inspection
Critical to clarify communication, enhance professionalism, ensure safety
Proper building construction terminology
Goes a step beyond the basic preplanning
Prefire analysis
Number one priority when considering the risks to any particular situation
Firefighter safety
Two main subjects that firefighters must throughly understand
- Fire behavior
- Building construction
Greatest of all firefighter enemies
Gravity
The eternal enemy of every building
Gravity
Load may be a ___ load and a ___ load at the same time
- Live load
- Impact load
KIP =
1000 lbs
Four types of forces
- Compression
- Tension
- Torsion
- Shear
Fire resistance is closely related to ___
Mass
Live loads are any load other than ___
Dead loads
___ loads can be accurately calculated where as ___ loads are indeterminate
- Dead loads
- Live loads
Office floor must be able to sustain at least ___psf as well as have the ability to sustain a load of ___psf at a specific location for individual collected heavy objects
- 50 psf
- 2,000 psf
Water weighs
8.34 lbs/g
Type of collapse that is a particular hazard in the construction of concrete frame building
Progressive colapse
Two types of modifications that use distance as a means to minimize the effects of a bomb exploded near the building
- Locating building away from the street
- Placing bollards (posts) and barriers
Shear walls resist
Lateral loads
Two types of framing that resist lateral wind and earthquake loads
- Braced frame
- Moment frame
Heavy riveting of girders to columns from top to bottom of the frame is called
Portal bracing
Type of floor that is designed to stiffen the building against wind and other lateral loads
Diaphragm floor
Externally braced buildings are known as ___, as contrasted with Core construction
Tube construction
An axial load is ___ to the plane
Perpendicular
A structure will sustain its greatest load when the load is
Axial
An eccentric load is ____ to the plane
Perpendicular but does not pass through the center of the section
Expressed as Q`
Heat release rate (HRR)
Information needed to asses the fire load in terms of pounds/sqft (3)
- Weight of combustable material
- Caloric value
- Floor area
Btu
1 pound of water 1 degree F
Two estimates for caloric values are commonly used
Wood, paper =
Plastics/Combustable liquid =
Wood, paper = 8,000 Btu/lb
Plastics/Combustable liquid = 16,000 Btu/lb
Q` is usually expressed in terms of (3)
- Watts (W)
- Kilowatts (KW)
- Megawatts (MW)
Safety factors:
Steel =
Masonry =
Steel = 2 Masonry = 10
The oldest structural member
Beam
Load-carrying capacity of a beam is increased by
Square of it depth
Three types of beams
- Simple
- Continuous (supported at ≥ 3)
- Fixed
A diagonal member that supports what would otherwise be a cantilever
Bracket
A beam that supports other beams
Girder
A beam that carries the load on the exterior of a framed building between the top of one window and the bottom of the window above
Spandrel Girder
A beam that spans the opening in a masonry wall
Lintel
A series of closely spaced beams
Grillage
Moves loads laterally when its not convenient to arrange columns one above the other
Transfer beams
Compressive connecting members of a truss
Struts
Connections in a truss are called
Panel points
Doubling the length of a beam decreases its carrying capacity by
Half
Columns loose strength by the square of the change in
Length
Most effective shape of a column
One that distributes the material equally around the axis as far as possible from the center of the cylinder
Types of columns (3)
- Piers
- Long slender
- Intermediate
Known as Euler’s Law columns
Very long, thin columns
Formula for Euler’s Law
Pc = π2EI/L2
Pc = Critical load π = 3.1415 squared E = Modulus of elasticity of material I = Moment of inertia L2 = Length of column squared
Wind load is an example of this kind of force
Flexural force
Two divisions of walls
- Load bearing
- Nonload bearing
Load bearing wall common to tow structures
Party wall
Ways in which walls are braced or stiffened (4)
- Buttresses
- Pilasters
- Wall columns
- Cavity or hollow walls
Arches can have this many hinges
3
Vital part of a structures gravity resistance system
Connections which transfer the load from one structural element to another
Two general types of connections
- Pinned
- Rigid frame
Connections that redirect overloads to other sections of the building are known as
Plastic design
Steel hated to 1,000F elongates ___ inches per 100 feet of length
9.5 inches
Unprotected steel rods and cables fail at
800F
A residential structure will usually be designed for a floor load of about ___ to ___ psf
30 to 40 psf
Combines the function of a beam and a column
Arch
Defined as a line of columns in any direction
Bent
Fire that caused for a national push for model building codes
Great Baltimore Fire of 1904
Decides which materials will be used
Architect
Caissons are typically constructed of
Concrete
All building have 3 structural components
- Superstructure
- Substructure
- Foundation
Crosslot bracing rakers and tiebacks
Used to protect against collapse of soil walls during excavation
Ammonia is explosive in concentrations of ___ to ___
15 to 25%
32/16 panel
- Cover rafters at 32” apart
- Cover joists at 16” apart
Define:
- Board
- Dimensional lumber
- Timber
- Board = ≤ 2” thick
- Dimensional lumber = 2-4” thick
- Timber = ≥ 5” thick
Wet wood has ___ strength than dry wood
Less
When portland cement became available
1880
Cement is a component of
Concrete
One-fourth the weight of traditional concrete
Aerated autoclave concrete
Carbon contant:
- Wrought iron
- Cast iron
- Wrought iron = 0.2%
- Cast iron = 3-4% (very brittle)
Structural steel fails at about
1,000 to 1,100F
First sign of serious fire in a closed structure
Violent pressure failure of the windows
Resistance to tensile loads is directly related to the ___ makeup of a material
Cross-section
Three negative characteristics of structural steel
- Conducts heat
- Elongates
- Fails at about 1,000 to 1,100 F
The insurance industry took the lead and prepared this in 1906
National Building Code
NFPA organized in
1896
Fire codes and building codes are updated every
3 years
Two of the most important test standards
- ASTM E-119
- ASTM E-84
___% of a building codes deals with fire safety
75%
Building construction Type 1A is fire resistive construction with a ___ hour fire rated structural frame
3 hour
NFPA 5000 uses an additional three-digit numbering scheme to designate the subcategories of each type of construction
- 1st number
- 2nd number
- 3rd number
- 1st number = Load bearing walls
- 2nd number = Beams and columns
- 3rd number = Floor construction
Three components of a means of egress
- Exit access
- Exit
- Exit discharge
Fire rating for corridors leading to a public way
1 hour
Generally a max travel distance of ___ ft to get to a fire rated stairway or exit
200’
In Group R occupancies windows must be a min of ___ sq ft with a min of ___ in. in width and ___ in, in height
- 5.7 sq ft
- 20 inches wide
- 24 inches high
Two types of elevators
- Electric cable
- Hydraulic piston
Occupant evacuation elevators are intended for the self-evacuation of occupants in building more than ___ ft in height
420 feet
Fire service elevators are found in new buildings taller than ___ ft and have a minimum lobby area of ___ sq ft
- 120’
- 150 sq ft
Horizontal exits have fire rated walls that are typically rated at ___ hrs
2 hours
Four essential elements of fire
- Fuel
- Oxidizing agent
- Heat
- Uninhibited chemical chain reaction
Four stages of fire
- Incipient
- Free burning
- Flashover
- Smoldering/decay
Primary factor influencing a fire
Oxygen supply
Construction factors influencing fire behavior (5)
- Combustible interior finishes
- Vertical openings
- Height of the room
- Proximity of wall to each other
- HVAC system
Aluminum will melt at around
1,200F
Fire growth contents problem can rest from any of the following elements (3)
- Furnishings
- Interior finish/decorations
- Mercantile stock
Commonly used as insulating sheathing on wood-framed building or as soundproofing
Fiberboard
Three way in which interior finishings may increase the fire hazard
- Increase fire extension by surface flame spread
- May generate smoke and toxic gases
- May add fuel to the fire contributing to flashover
Key factor in a five alarm fire in the Empire State Building
Cork paneling
Robertson protected metal
Asphalt-coated steel
A defective ballast in fluorescent light fixture can reach temps of
1,500F
Often provides the first warning of most fires
Smoke
HCN
Hydrogen Cyanide
HCN is believed to be as great a danger as
CO
Exposure in which the concentration (ppm) x minutes exposed = 33,000 is likely to be dangerous
Harber’s rule
Most common toxic fire gas
CO
Research at NIST has pointed out that CO can be generated up to ___ times as much in enclosed voids as in the open
50 times as much
Most expensive by-product of fire suppression
Water
From a historical perspective ___ has always been a primary objective
Fire containment
Limiting fire spread from building to building is accomplished through several means (5)
- Restrictions on area/height
- Limits on the combustibility of roofs and exterior wall surfaces
- Minimum separation distances between buildings
- Limits on openings in exterior walls
- Fire-resistive exterior walls
A primary concern in fire protection
Life safety
Most important elements of life safety (2)
- Proper means of egress
- Protection against hazards
Generally accepted indications of imminent collapse (4)
- Floors/roofs softening
- Water flowing through bricks
- Smoke pushing out through mortar
- Strange noises
What fire resistance does not provide (3)
- Life safety
- Smoke control
- Protection of dollar loss
Standard time-temp curve is unchanged for more than ___ years
80 years
Time-temp curve:
- 5 min
- 1 hr
- 4 hr
- 5 min = 1000F
- 1 hr = 1700F
- 4 hr = 2000F
Flame spread over reinforced concrete board
0
Flame spread is classified as:
- Class A =
- Class B =
- Class C =
- Class A = 0 - 25
- Class B = 26 - 75
- Class C = 76 - 200
Materials with a smoke-developed rating ___ can be expected to generate substantial amounts of smoke
≥ 300
Critical Radiant Flux Test measures
- A materials ability to resist flame spread
- The higher the CRF number the less flammable
2 classes of interior floor finish ratings
Class I =
Class II =
- Class I = CFR minimum ≥0.45 watt/sq cm
- Class II = CFR minimum ≥0.22 watt/sq cm
Developed to monitor vibrations in a structure that might be a precursor to collapse
HOBS, Health of Burning Structures
In a simulated basement fire an exposed wooden I-beam collapsed in ___min
6:03 minutes
Fire resistive assemblies (3)
- Fire walls (2-4 hr)
- Fire partitions (1 hr)
- Fire barrier (1-2 hr)
Fire door ratings range
20 min - 3 hr
One of the most important aspects of a fire door
Its ability to close and latch closed
Fire doors close by 3 methods
- Swinging (most common)
- Sliding
- Rolling
Two types of fire door closure devices
- Self-closing
- Automatic
Inspections of fire doors should include the following (6)
- Operating fire door and shutters
- Raising the counterweight to ensure door closes
- Inspecting doors for damage
- Inspecting all hardware
- Checking the fusible link
- Checking the proper operation of “door coordinators”
4 major classes of sprinkler systems
- Wet pipe
- Dry pipe
- Preaction
- Deluge
Sprinkler systems are ___ designed
Hydraulically