9 Steel Construction Flashcards Preview

Building Construction Related To The Fire Service > 9 Steel Construction > Flashcards

Flashcards in 9 Steel Construction Deck (51)
Loading flashcards...

Mass of steel reduced failure rate in fires, therefore, beam and girder type rigid connections

Are less prone to failure


Gusset plates

Metal or weeded plate used to connect and strengthen intersections of meal or wooden truss components


Gusset plate also increases what at the connection

Mass, therefore decreasing the possibility of failure


In gabled rigid frame what is the strongest part of the roof and wall

Knee joint, last to fail


On older buildings, steel framework was encased in brick or concrete. Steel column encased in 3 inches of concrete with siliceous aggregate would have a fire rating of

4 hrs


In modern applications the most common used insulation, or fire resistance, is

Gypsum, sprayed materials, and intumescent coatings


Some fire resistance is applied by spraying and are known collectively as

Spray applied fire resistant materials SFRMs


A type of gypsum with additives like glass fibers to increase fire resistance used where specific requirements are needed

Type x gypsum.


Fire resistance value of gypsum is from

It's worse content, 21%


Most common forms of SFRMs are

Mineral fiber
expanded aggregate coatings such as vermiculite and perlite


Spray on fire resistance is based on type and thickness of material, applied proofing can rage from what thickness and fire rating

7/8- 1 7/8" with fire rating of 1-4 hrs



Containing or composed of cement, with cement like characteristics


Cementitious ingredients can include

Portland cement, gypsum, perlite, and vermiculite
Some manufacturers use magnesium oxychloride, oxysulfste, calcium aluminate, phosphate , or ammonium sulfate
Density ranging from 15-50 lb/cubic ft


Intumescent coating

Coating or paint like products that chars, foams, and expands when exposed to heat creating insulating barrier. Expanding 15-30 times


Mastic coating reacts similar to

Intumescent coatings, but are complex and organic


Intumescent coatings have a thickness of

0.03 to 0.4"


Membrane ceiling

Suspended insulating tile ceilings to provide fire resistance of 1-3 hrs as a rated ceiling assembly


Ceiling assemblies aren't rated individually but rather as part of a floor and ceiling assembly, penetration of the ceiling can

Severely reduce or eliminate the fire rating


Reduction in fire code requirements examples

Eliminating fire resistance requirements for roof members 20 ft or higher over floor
Allowing reduction in fire resistance when building is sprinklered when not normally required.


In IBC building type ratings, the letter designation afterward indicates fire resistance, type II A vs type II B, which is more resistant

Type a is more resistant than type b


Fire resistance of steel depends on

Mass of steel and degree of fire resistance provided