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Nezero
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Homework Statement
A 10 storey building has columns spaced on a 8m by 10m grid.
a) Calculate the reaction at the base of an internal column assuming a 300mm thick concrete floor slab and a live load of 3.0kPA (ignore self weight of column and assume concrete density 2.4t/m^3
b) Assuming an allowable axial stress of 20MPa in the reinforced concrete column estimate the size of column assuming a square cross section
Homework Equations
P=F/A
Volume * density = mass
The Attempt at a Solution
Well, I'm a bit confused by the wording of the question firstly.
So there is an 10 storey building with a concrete floor slab which is 8m by 10m with 300mm thickness right. So there is one column supporting this floor slab.
Firstly I calculated the mass of the slab which is 8 * 10 * 0.3 * 2.4 = 57.6tons
So the weight of that is 57600 * 9.8 = 564.48kN
So the column must support that + the live load.
Live load = 3000 Pa.
P= F/A
F=PA
F= 3000 * 8 * 10 / 1000 = 240kN
So total reaction force = 564.48kN+ 240kN = 804.48kN
Now there are no answers so I can't check this. Is this right?
b)
So is P = 20MPa
P = F/A
F= 804.48kN
A= 804.48kN/20MPa = .040224m^2
Sqrt(A) = 0.2m
So 0.2 by .02 m?