Collapse of BB CH10 Easy

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Questions and Answers

What is the size of the noncombustible construction garage?

250x250 feet

100x100 feet

150x150 feet

200x200 feet (correct)

What action does the battalion chief order the ladder company to perform?

Search for occupants inside the building

Enter the building through the front doors

Vent the roof (correct)

Assist the engine company with the hoseline

What does the firefighter do after reaching the top of the ladder?

Enters the building through a skylight

Swings the circular saw over the parapet wall (correct)

Calls for backup from the second unit

Uses the pike pole to break a window

What type of roof construction does the text describe?

Steel bar joist and C-beam Signup and view all the answers

What tool does the firefighter use to cut through the steel roof deck?

High-speed carbide blade Signup and view all the answers

What color sparks are generated when the firefighter cuts through the steel roof deck?

Blue-white Signup and view all the answers

What does the firefighter use to lift the cut portion of the roof?

Pike pole Signup and view all the answers

What happens to the roof section as the firefighter completes the final cut?

It sags and nearly falls into the fire Signup and view all the answers

What causes the roof to collapse and flames to erupt?

Flames erupt from the vent hole Signup and view all the answers

What happens to heated steel during a fire according to the text?

It can distort and lose strength Signup and view all the answers

What is a characteristic of steel during a fire, based on the text?

It does not melt but can expand, bend, twist, and sag Signup and view all the answers

What has been the trend in the use of steel in buildings since World War II?

Increased use, replacing wood and masonry Signup and view all the answers

What is a drawback of lightweight steel buildings during fires, as mentioned in the text?

They can collapse rapidly if the steel distorts and moves Signup and view all the answers

What has the trend towards lightweight buildings led to, according to the text?

More steel buildings and less concrete Signup and view all the answers

What is a hazard posed by spalling during a fire?

Concrete chunks falling Signup and view all the answers

What is a potential issue with the 'membrane ceiling' method?

Missing or improperly placed panels Signup and view all the answers

What danger exists with a membrane ceiling if not properly constructed?

Collapse danger Signup and view all the answers

Which method is described as the least effective for protecting steel from fire heat?

Spray-on fire-retarding material (SFRM) Signup and view all the answers

What have post-fire investigations shown about SFRM?

Ineffective in protecting steel for the designated time Signup and view all the answers

What is the material sprayed on steel today for fire protection?

Slurry of vermiculite, volcanic rock, or mineral fiber mixed Signup and view all the answers

Why is the spray-on fire protection method still preferred for new buildings despite its ineffectiveness?

Less expensive and faster Signup and view all the answers

What effect do applications of primer paint on steel have on the adhesion of spray-on fire retarding effectiveness?

Reduce adhesion by one third to one half Signup and view all the answers

What is a common issue with the spray-on slurry for fire protection?

Not mixed properly and may not be applied evenly Signup and view all the answers

What can cause the fire-retarding spray-on to blow off and leave the steel unprotected?

Vibrations and HVAC air movement Signup and view all the answers

What aspect of the spray-on insulation for steel structures has been questioned?

Thickness Signup and view all the answers

What is the failure temperature range of steel?

1,000 to 1,100 degrees Fahrenheit Signup and view all the answers

Which material has greater tensile and compressive strength than steel?

Aluminum Signup and view all the answers

What are examples of shaped steel structural elements mentioned in the text?

Bar joist trusses and C-beams Signup and view all the answers

What was the primary material used in the construction of the World Trade Center?

Shaped steel Signup and view all the answers

What are three common methods to protect steel from fire mentioned in the text?

Encasement with concrete, installation of a fire-retarding ceiling, and applying a spray-on fire retarding material Signup and view all the answers

What is the drawback of using concrete encasement to protect steel from fire?

Chunks of concrete potentially collapsing during a fire Signup and view all the answers

What organization conducts tests to evaluate protection methods of insulating steel from fire?

The National Fire Protection Association Signup and view all the answers

What is the standard time temperature test fire used in fire protection testing laboratories?

A compilation of test fires conducted in 1918 Signup and view all the answers

What type of testing is used by testing laboratories to rate steel fire resistance?

Small samples of floor sections or wall areas testing Signup and view all the answers

What is the reaction of the text to the time temperature furnace test fire used by testing laboratories to rate steel fire resistance?

It is questioned Signup and view all the answers

What is the primary concern regarding the use of concrete encasement to protect steel from fire?

Structural integrity Signup and view all the answers

What is the primary advantage of shaped steel in building construction?

It allows for lighter weight steel buildings Signup and view all the answers

What type of buildings are constructed with large rectangular windows at the upper portion of the masonry or corrugated steel enclosure walls?

One-story, noncombustible buildings using lightweight steel joists Signup and view all the answers

What is the advantage of ventilating several windows in one-story, noncombustible buildings with lightweight steel joists, as mentioned in the text?

Faster and safer smoke venting compared to making a 4x4-foot roof cut Signup and view all the answers

What is the safety hazard to firefighters when a different roof construction, such as lightweight steel bar joists, is introduced into a community?

The steel bar joist will collapse more quickly Signup and view all the answers

Why is it mentioned that an experienced firefighter cannot transfer their sense of safe operating time to a building with a lightweight steel roof?

Due to the different collapse characteristics of lightweight steel roofs Signup and view all the answers

What determines steel failure during a fire?

Load stress Signup and view all the answers

What are roof support systems in noncombustible buildings designed to support?

Rain or snow accumulation Signup and view all the answers

What can influence the collapse of steel joists during a fire?

Roof decks such as lightweight insulation or precast concrete planks Signup and view all the answers

What impact does the mass of steel elements have on fire resistance?

Increases fire resistance Signup and view all the answers

What property does large-size steel have that aids in fire resistance?

It absorbs and transfers heat away from flame contact Signup and view all the answers

What is the primary concern regarding Type II noncombustible unprotected steel buildings?

Not suitable for high hazard occupancies Signup and view all the answers

What is the primary characteristic of steel in fires according to the text?

It will collapse from the effects of fire without protection Signup and view all the answers

What affects the rate at which steel reaches its critical temperature during a fire?

Fire size Signup and view all the answers

What is the impact of increasing the mass of a steel element on its fire resistance?

Increases fire resistance Signup and view all the answers

What are modern roof joists in noncombustible buildings not designed to support?

The same load as floors Signup and view all the answers

What is the primary limitation of roof support systems in noncombustible buildings?

They are not designed to support the weight of firefighters and their equipment Signup and view all the answers

What is the impact of load stress on steel during a fire?

It determines steel failure Signup and view all the answers

What is the failure temperature of steel in a fire?

1,100 degrees F Signup and view all the answers

What is the primary factor influencing unprotected steel's failure in a fire?

Fire temperature Signup and view all the answers

What is the primary concern for firefighters regarding lightweight steel bar joists in noncombustible construction?

Significant dangers of collapse Signup and view all the answers

What is the impact of steel's ability to conduct heat and expand during a fire?

Structural collapse Signup and view all the answers

What is the reason for the wide spacing of steel bar joists in noncombustible construction increasing the risk of firefighters falling through roof openings?

Lack of support for firefighters' weight Signup and view all the answers

Why are fire protection systems essential in noncombustible buildings with high fuel load ratings?

To prevent rapid destruction by fire Signup and view all the answers

What is the impact of traditional assumptions about roof construction no longer holding true?

Necessity for awareness of collapse potential Signup and view all the answers

What is the primary reason for the compromised ability of firefighters to gauge the safety of a burning building in Type II noncombustible construction with steel trusses?

Incorrect size-up of fires Signup and view all the answers

What is the potential consequence of the lack of fire resistance in noncombustible steel buildings?

Rapid destruction by fire Signup and view all the answers

What is the purpose of the time-temperature test fire?

To provide insight into the rapid rise in temperature during a fire Signup and view all the answers

What is the primary influence on the increased incorrect size-up of fires in noncombustible Type II construction in the US?

Lightweight steel bar joists Signup and view all the answers

What is the potential hazard posed by the failure of unprotected steel in a fire?

Structural instability Signup and view all the answers

Study Notes

Steel Shaping and Fire Resistance in Building Construction

Steel has greater tensile and compressive strength than wood or masonry and can be shaped more easily
Shaped steel has greater loadbearing capacity and allows for lighter weight steel buildings
Examples of shaped steel structural elements include bar joist trusses and C-beams
The World Trade Center was constructed mostly of shaped steel
The failure temperature of steel is in the range of 1,000 to 1,100 degrees Fahrenheit
The National Fire Protection Association conducts tests to evaluate protection methods of insulating steel from fire
The standard time temperature test fire is a compilation of test fires conducted in 1918 and is used in most fire protection testing laboratories
The standard furnace fire tests use only small samples of floor sections or wall areas to determine a structural element's reaction under fire conditions
There is no full-scale testing that simulates an actual building in an actual fire
The time temperature furnace test fire used by testing laboratories to rate steel fire resistance is questionable
Three common methods to protect steel from fire are encasement with concrete, installation of a fire-retarding ceiling, and applying a spray-on fire retarding material
Concrete encasement is considered the best method to protect steel from fire, but it has the drawback of chunks of concrete potentially collapsing during a fire

Dangers of Unprotected Steel in Noncombustible Construction

Firefighters' ability to gauge the safety of a burning building is compromised in Type II noncombustible construction with steel trusses
Incorrect size-up of fires is increasing due to changes in noncombustible Type II construction in the US
Lightweight steel bar joists in noncombustible construction pose significant dangers to firefighters
Wide spacing of steel bar joists in noncombustible construction increases the risk of firefighters falling through roof openings
Traditional assumptions about roof construction no longer hold true, and firefighters must be aware of collapse potential in different types of construction
Unprotected steel's failure in a fire is influenced by factors such as fire temperature, load stress, steel thickness, and fire size
Noncombustible steel buildings can be quickly destroyed by fire due to the lack of fire resistance
The failure temperature of steel is considered to be 1,100 degrees F, causing a significant loss in load-carrying capacity
Steel's ability to conduct heat and expand during a fire can lead to structural collapse
The time-temperature test fire provides insight into the rapid rise in temperature during a fire
Firefighters need to understand the heat generated by fires and the potential impact on steel structures
Fire protection systems, such as sprinklers and fire partitions, are essential in noncombustible buildings with high fuel load ratings

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Description

Test your knowledge on steel shaping and fire resistance in building construction with this quiz. Explore the advantages of shaped steel, its use in iconic structures like the World Trade Center, and the methods to protect steel from fire, including the drawbacks of each method.