RC VS. STEEL
RC VS. STEEL
(OP)
I am conducting a study about structural framing materials and I am focus on reinforced concrete (RC) and Structural steel (Wide Flange Section). My idea is to consider a frame model and design it as reinforced concrete and steel then compare the results.
I have a problem in generating my model, since in reinforced concrete, the ground floor columns are fixed to the pedestal going to the footing; but in steel framing system, the ground columns are connected by base plate to the pedestal and usually hinged. It seems that i dont have a common structure since for RC the ground columns are fixed and hinged for steel.
Am I correct in my assumptions? Is there something that I forgot to consider? I am only comparing the superstructure of the building.
I need to hear your smart opinion guys. Thanks..
RLC
I have a problem in generating my model, since in reinforced concrete, the ground floor columns are fixed to the pedestal going to the footing; but in steel framing system, the ground columns are connected by base plate to the pedestal and usually hinged. It seems that i dont have a common structure since for RC the ground columns are fixed and hinged for steel.
Am I correct in my assumptions? Is there something that I forgot to consider? I am only comparing the superstructure of the building.
I need to hear your smart opinion guys. Thanks..
RLC






RE: RC VS. STEEL
RE: RC VS. STEEL
RE: RC VS. STEEL
RE: RC VS. STEEL
My intention is to compare steel and RC as structural material for framing system considering cost, construction time frame and story drift. In doing so, I would like to meet standards in structural design and standard construction practice.
civeng80,
the common assumption in steel design is that the column is pinned connected to the base plate, but in reinforced concrete it is poured monolithically and usually assumed as fixed. Please ilaborate your idea.
RE: RC VS. STEEL
Partial fixity = 0.4EI/L
This was based off the old K values used for column design. I don't know how applicable the equation is today. You would have to make that determination.
Also, the PCI design handbook has an equation for developing the spring resistance of a base plate based off the column size, base plate geometry/thickness, anchor bolt length/position/thickness, and footing size/soil sub grade modulus. I'm not sure if you can use a version of this equation in you analysis.
RE: RC VS. STEEL
RE: RC VS. STEEL
RE: RC VS. STEEL
If spread footings, I would never consider it to be fixed. Depending on the ground conditions it may be possible to generate some fixity with footings into solid rock. Otherwise, pinned.
If piles, it would depend on the filing arrangement whether or not fixity can be generated.
If it is a raft slab, you do not get full fixity. This should come out in the 3D analysis..
RE: RC VS. STEEL