circular concrete column capacity?How economical?
circular concrete column capacity?How economical?
(OP)
What is the capacity of a 600 mm dia concrete column.Is this a reasonably economical size for a 4 storey building (5.5m x 8 m typical floor layout). The rebar used are 15 Numbers 25 mm High yield=460N/mm2(15Y25) and the concrete grade is 30N/mm2. Dead load =6 kn/m2 Live load=3Kn/m2.






RE: circular concrete column capacity?How economical?
You would have to do the load take down calcs taking into account the roof and floor construction, finishes, live load requirements etc. And then in terms of column sizing the most important thing governing size is usually the applied moments. Vertical loads often help resist moments so you need to look at the axial, moment load interaction. There are published tables or graphs of column axial and moment load interactions. I think BS8110 part 3 has them and once you've worked out your loads you could look at these.
Carl Bauer
www.bauerconsultbotswana.com
RE: circular concrete column capacity?How economical?
Is it true to say the axial load is the overall load on and above the considered floor level and the moment is for that particular floor level only
RE: circular concrete column capacity?How economical?
In any case, be confident in results gained from code application, as long in the safety side.
RE: circular concrete column capacity?How economical?
In other words, for all the beginners out there, don't assume that the maximum of everything controls!
RE: circular concrete column capacity?How economical?
RE: circular concrete column capacity?How economical?
RE: circular concrete column capacity?How economical?
Please check out the following website for a free circular column design spreadsheet to BS 8110:
http:\\www.technouk.com
It also has links to other good sites.
Best Regards
Angus
RE: circular concrete column capacity?How economical?
As you might surmise by some of the comments given herein, the design of columns is very sensitive to the type of loading applied.
You should not even attempt to size your columns until all applied loads have been determined, such as contributing floor loads coupled with the bi-axial bending that can occur when the wind is applied at 45 degrees to the structure. Properly installed shear walls can relieve part of this, but you will always have a certain amount of bending applied to the columns.
Then, as Qshake suggested, you must find the applied eccentricity and use those values to size the member. You can find some design aides for this (including software) at the following sites (Prestressed Concrete Institute, Portland Cement Association & American Concrete Institute):
http://www.pci.org/
http://www.portcement.org/soft/soft_col.asp
http://www.aci-int.org/booktemp/main.htm
http://www.spiraleng.com
If you wish to visit my website, we can discuss these or other issues further.