2 Structural Fire Resistance Building Classifications Flashcards
(86 cards)
Fire resistance
The ability of structural assembly to maintain its load bank and structural integrity under fire conditions
Combustibility
Nature of the building structural system will impact the rate of fire growth
Fire resistance rating
Reading assigned to a material or an assembly after standardized testing by independent organization that identifies amount of time material or assembly of materials will resist a typical fire as measured on standard time temperature curve
In addition to classifying buildings by construction type building codes by
Their occupancy
In the case of walls petitions and ceilings fire resistance also means
The ability to act as a barrier to fire
True/false fire resistive construction is not prone to structural failure under fire conditions
True
Building codes will have requirements for fire resistance for these structural elements
Beams, columns, walls and partitions, floors and ceiling assemblies, roof and ceiling.
Building code will typically require the columns supporting floors and the fire was just a building the fire resistance rating of
Three hours
Walls enclosing a exit stairwell typically have a fire resistance rating of
One or two hours to protect the stairwell
There are three means by which the fire resistance of structural assemblies can be determined
Conducting standard fire resistance testing laboratory
Performing analytical calculations to determine the resistance to a standard fire test
Employing analytical structural fire engineering design methods based on exposure characteristics
The most commonly used method of determining fire resistance is
Laboratory test
The earliest known fire test on building materials were conducted in Germany
1884 to 1886
In the United States the first known fire test were conducted in
Denver Colorado 1890 with subsequent test in New York City 1896
NFPA 251
Standard method of tests for fire and durance building construction and materials
NFPA 251 is also designated as
ASTM E-119
What is the temperature curve in a fire resistance test furnace
1000° at five minutes, 1550° at 30 minutes 1700° at one hour, 1850° at two hours, 2000° at four hours, 2300° at eight hours
Because components are you there structural loadbearing or not the test results will be classified as
The bearing or non-non-bearing based on their intended use
The strengths and floor and ceiling assembly is affect the extent to which an assembly may
Rotate or expand exposed to temperatures affecting his ability to support a load
Structural fire systems test conducted they continue until
The specimen fails for the specified fire endurance for which the specimen being tested his reachEd
Primary points of failure for fire resistance test are
Failure to support and applied load, temperature increase on unexposed side of fall floor and roof of 250° above ambient temp
Passage of heat or flame through assembly enough to ignite cotton waste
Excessive temperature on steel numbers
Underwriters laboratory
Independent fire research testing lab that certifies equipment and materials
Failure point temperature on steel will depend on
How the steel is being used
Fire resistance rating for test specimen including fire doors and windows are in standard intervals of
15 minutes, 30 minutes, 45, one hour, 1.5 hour, two hours, three, four hour
Rated assemblies may perform differently in actual situations because
In the real world workmanship and materials encountered may vary