Exist. Bldg with ASTM A53 Gr A Columns

[wallerdf]

I have an existing building built in 1979 with 4x4x3/16 columns which the general notes state ASTM A53-52T Grade A. The loads added to the existing building are greater then the 5% increase allowed therefore I need to bring the existing lateral system up to code. I wanted to try and use these columns but not sure if I should since Gr A is not listed in the 13th edition.

 

[SeanMD]

I don't know why you couldnt use them. Can you find the material specs from a previous AISC manual?

 

[BigH]

why not check ASTM to see what the properties are?

 

[wallerdf]

I have the properties from ASTM:
Fy = 30 ksi min.
Fu = 48 ksi min.

I guess what I was wondering is if they could be used since I need to bring the building up to code and that designation is not in the current AISC manual. If it's not in the manual is it unusable per current code?

 

[paddingtongreen]

Absolutely you can use it. We would be tearing down buildings all over the place if old specifications were not grandfathered.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[JedClampett]

Isn't A53 a pipe (round only) specification? From your description, it sounds like square tubes were used. Either someone referenced the wrong specification or the design was changed.
The good news is that it's likely that the square sections have higher yield properties than A53.

 

[wallerdf]

I noticed that also. I went back to the sixth edition (1963)and found that structural tubing was available in ASTM A7 or ASTM A36. I also went back to the seventh edition (1970)and found that structural tubing was available in ASTM A501 (Fy=36ksi) and ASTM A500 Gr B (Fy=46ksi). I guess it could be A7 but i think I should be able to use Fy=36ksi based on the building date. It would probably be a good idea to get some of the columns tested to be sure. Thanks everyone.