Steel Flashcards
Which is stronger? Mild steel or cold-rolled steel?
Cold-rolled steel
How is mild steel different from cold-rolled steel?
It is drawn out hot
When is mild steel used?
Most structural steel components
When is cold-rolled steel used?
Bridge cabling, cross bracing, cables for prestressing concrete & stud framing
Which has more carbon? Cast iron or wrought iron?
Cast iron
What effect does too much carbon have on steel?
Hard but brittle
What effect does too little carbon have on steel?
Malleable but weaker
What is the difference between a girder and a beam?
Girder is primary to a beam
Girders support beams
How deep should a steel beam for 60’ be?
Beam depth is 1/20th of the span
So for 60’ = 3’
How deep should a girder be?
Girder depth is 1/15th of the span
How wide should a beam / girder be?
1/3 it’s depth
How deep should open web steel be?
1/20th the span
How deep should roofs and lightly loaded floors?
1/24th the span
How deep should steel decking be?
1/24” the span with concrete topping
How deep should a triangular steel truss be?
1/4 span
How deep should a rectangular steel truss be?
1/8th span
What is added to steel to make stainless steel?
Nickel and chromium
What is a castellated beam?
When a beam is cut along the web and then re-welded back together
What does W12 mean in a steel beam W12 x 120
12” deep
What does 120 mean in a steel beam W12 x 120
120 lbs per linear foot
What is a LH bar joist?
A long span bar joist, 96’
What is a DLH bar joist?
A deep long span bar joist, 150’
What is a K bar joist?
Most common, up to 60’
What is a ‘slip-critical’ bolt type?
A bolt that is preloaded so friction resists movement
What is a ‘bearing-shear’ bolt type?
Snug-fit and movement is assumed. This type is super tight and operates in tension.
Why are washers used?
To prevent tearing or galling
What is the difference between a shear connection and a moment connection?
Shear handles gravity
Moment handles bending
How can you tell if a connection is a moment connection?
The flanges and web are engaged.
How can you tell if a connection is a shear connection?
Just the web is engaged. The flange is free.
What can be used to strengthen a column is a beam bearing on it is too heavy?
Stiffener plates
When are back-up bars used?
For welding
How do you connect 2 columns together?
A column splice
What is used to connect a steel column into the foundation?
A steel base plate
When are dog bone cuts used and what are they for?
In seismic zones
Controls where the deformation in a seismic event
Is a complete moment resisting frame is too expensive, what can be used instead?
Braced frame
When is an eccentrically braced frame used?
In seismic areas as it can resist lateral forces without buckling
What is beam cambering?
Pre-curing something so that once loaded it is flat and better resists loads
When does a steel element NOT need to be fire treated?
When it is only for lateral forces
List the galvanic numbers from 1 to 9
ZAS IST PICS
- Zinc
- Aluminum
- Steel
- Iron
- Stainless Steel (Active)
- Tin
- Lead
- Copper
- Stainless Steel (Passive)
Is a galvanic number 1, anode or cathode?
Anode
is a galvanic number 9, anode or cathode
Cathode
Is anode or cathode more active?
Anode is more active
Cathode is more inactive
If a surface is anodic and the fastener is cathodic, is this an issue?
Not particularly
If a surface is cathodic and the fastener is anodic, is this an issue?
Yes - the fastener will see more galvanic action and likely cause breakage
