medium_span_steel Flashcards
(20 cards)
What is the primary advantage of structural steel?
High strength and ductility (not brittle)
Why is ductility an important property for structural steel?
It allows the structure to flex slightly during wind or earthquakes without failing
What is the primary disadvantage of structural steel in fire conditions?
Steel melts and loses strength at high temperatures
How is fire protection typically provided for structural steel?
Drywall encasement or spray-on fireproofing
What is meant by ‘structural steel’?
Refers to wide flange shapes and other structural members, not light gauge studs
What is the typical shape used in structural steel for mid-span applications?
Wide flange (I-beam) sections
What is the function of the web in a wide flange beam?
To hold the top and bottom flanges apart, adding depth and stiffness
What is the typical span range for wide flange beams?
25 to 45 feet (sweet spot: 30–35 feet)
Why are 30–35 foot spans popular in office and retail construction?
They provide flexible open space for various layouts
What structural steel system allows ductwork to pass through the structure?
Open-web steel joists
What is the typical depth range for open-web steel joists?
24 to 36 inches
What are the typical span capabilities of open-web steel joists?
25 to 60 feet
Why are open-web steel joists more common in roof construction?
They are lighter, and roof loads are lower so bounce is less critical
What type of fire protection method reacts chemically to absorb heat?
Gypsum-based materials like drywall
What is one limitation of open-web joists in structural loading?
Lower point load capacity compared to wide flange beams
What installation challenges are associated with structural steel?
Requires cranes, specialty trades, bolting, welding, and skilled labor
What is a unique historic method once used to fireproof steel columns?
Filling steel tubes with water to absorb and distribute heat
What determines if fireproofing is required on exposed structural steel?
Proximity to potential heat sources and building height (based on code)
How often are open-web steel joists spaced compared to wide flange beams?
More frequently (4–8 ft on center vs. 10–20 ft for wide flanges)
Why is structural steel ideal for medium spans?
Offers strong, reliable performance and can span 30–35 feet efficiently
