Ch. 2 Structural Fire Resist. and Bldg Class. Flashcards Preview

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Flashcards in Ch. 2 Structural Fire Resist. and Bldg Class. Deck (45):
1

What will impact rate of fire growth?

Combustible nature of bldgs structural system

2

Determines likelihood of structural collapse under fire conditions.

Fire resistance

3

Classifications of buildings based on:

-fire resistance
-combustibility

3

Fire resistance is a function of the properties of all materials used, including (5)

Combustibility.
Thermal conductivity.
Chemical composition.
Density.
Dimensions.

4

In the case of ________, ________ and ________, fire resistivity also means the ability to act as a BARRIER to fire.

Walls.
Partitions.
Ceilings

6

In addition to classifying buildings by construction type, building codes classify buildings by:

Their occupancy

6

MOST COMMONLY used method for determine fire resistance ratings is: (aka Most Often)

Laboratory test

(other 2: analytical CALCULATIONS and analytical structural fire engineering DESIGN METHODS)

7

Fire resistance of structural components can be evaluated ________ and is known as the fire resistance rating. Expressed in _______ and _________.

Quantitatively

Hours and FRACTIONS of hours

8

Standard method of tests of fire endurance of bldg. constr. and materials

NFPA 251 or ASTM E-119
Could be too severe or not severe enough

*UL test furnace 14x17 ft. for beams, floor and roof assemblies*

9

Time scale for standard fire test: 5 min, 30 min and 1 hr

5 min = 1,000F.
30 min = 1,550F.
1 hr = 1,700F.

10

Structural specimen is tested, test is continued until _______ OR ________________.

Specimen fails.
The specified fire endurance is reached

11

Primary points of failure for (furnace) test: (4)

Failure to support applied load.
Temperature increase on UNEXPOSED side of WALL, FLOOR or ROOF, 250F above ambient.
Passage of heat/flame through assembly to ignite cotton waste.
Excess temperature in steel members.
*certain walls/partitions subjected to hose stream*

12

In actual situations, may perform satisfactorily for longer or shorter periods of time. Variation due to:

Differences in workmanship AND
Materials encountered in the real world

13

Standard test fire assumes:

ENDLESS fuel supply.
ADEQUATE ventilation.

14

Standard test evaluates the ability of structural assemblies to _______ and to ______.

-carry a structural load.
-act as a fire barrier.
*not for smoke, assemblies other than those tested, joints*
(Joints UL 2079)

15

Fire testing organizations

Intertek Testing.
Cal Berkeley, Forest Products Lab.
Armstrong cork Co.
National Gypsum Co.

16

ASCE/SFPE 29 is standard for _______.

Calculations of fire resistance (mathematical)

17

Std method for behavior of materials VERTICAL TUBE at 750F

ASTM E136
*most common test for determining COMBUSTIBILITY*

18

Codes make use of _______ but do not make use of ____.

Numerical designations
Descriptive terms

19

What does Bldg Constr and HOT call type/class III?

BC = EXTERIOR PROTECTED (masonry)
HOT = ordinary (brick and wood joist)

20

Most significant characteristic of bldg construction:

How it behaves under fire conditions

*bldgs CLASSIFIED how they behave under fire conditions*

21

In NFPA 220, each classification is designated by a ______ code. The first digit refers to _____. The second digit refers to ____. The third digit refers to ____.

3-digit code
First-exterior bearing walls
Second-structural frames, columns and girders (more than 1 floor)
Third-floors
**BFCGF**

22

Type I required fire resistance
- walls, columns and beams =
- floors =
- roof deck/supports =
- interior partitions =

Type I
wcb = 2-4 hrs
floors = 2-3 hrs
roof deck/supports = 1-2 hrs
interior partitions/stairwells/corridors = 1-2 hrs

23

Type I types of construction

I-A = 4.4.2
I-B = 3.3.2

24

2 most common methods of constructing Type I

-reinforced concrete
-protected steel frame

25

2 attributes of concrete that make it fundamentally fire-resistive

Inherently noncombustible material
Good thermal insulating properties

26

Most common characteristic of unprotected, noncombustible construction

Use of unprotected steel

27

Type II with degree of fire resistance referred to:

-protected noncombustible construction

28

2 subclassifications of Type II: Type II-A and II-B:

II-A = 1 hr fire resistance for STRUCTURAL components.
II-B = unprotected structural STRUCTURAL components.

28

Type II-
Point at which unprotected members fail depends on: (3)

-ceiling height
-size of members
-intensity/duration of fire

29

Type III
Frequently constructed with exterior walls of masonry but can be ________________.

Any noncombustible material with required fire resistance

31

Type III has III-A and III-B

III-A = 1 hr fire-resistive for INTERIOR MEMBERS (2.1.1), fire rating for structural components
III-B = no fire resistance for INTERIOR MEMBERS (2.0.0), unprotected steel sometime used

32

When III-A has to have fire rating, most common are:

-plaster in old
-gypsum board in new

33

Fundamental fire concern with Type III construction is:

Combustible concealed spaces
-between floor and ceiling joists
-between stud and partition walls
* essential that concealed spaces to be firestopped.*

34

2 distinctions between Type III and Type IV

Type IV beams, columns, floors and roofs made of SOLID wood with dimensions GREATER than Type III
Concealed spaces are not permitted between structural members in Type IV

35

Primary fire hazard with Type IV

Massive amount of fuel by large structural members
-in addition to building contents

36

Many Type V structures required to have ______ fire resistance for ________. Typically accomplished by_____ or ______.

-1 hour
-structural members
-plaster OR fire-rated gypsum board

37

In modern practice, wood frame buildings most often constructed using ___________.

-LIGHT-FRAME construction.
"common currency of small residential and commercial buildings in North America today"

38

______ is the product of the weight of the combustibles multiplied by their heat of combustion. Also used as a measure of potential heat release.

Fire Load = also known as Fuel Load
Expressed in pounds per square foot

39

A fire load does not translate into an equivalent ________.

Structural load

40

Classifying buildings according to ______ facilitates the administration of a code.

Occupancy

41

IBC residential occupancies (4)

R1-transient occupants
R2-permanent MORE than 2 units
R3-permanent LESS than 2 units (adult/child 5 or fewer for 24 hrs)
R4-assisted-living, 5-16 occupants

42

IBC Assembly occupancies (5)

A1-fixed seating-theater/concert
A2-consuming food/drink
A3-worship, recreation, amusement
A4-indoor sports
A5-outdoor-bleachers, grandstands, stadiums

43

IBC/NFPA common classes (ABEMRS)

Assembly
Business
Educational
Mercantile
Residential
Storage
*IBC-FHIU and NFPA-DHADRI*

44

Mixed occupancies-required separations from ____________ and not all occupancies require separation.

1-3 hours