Rebar strength in 1958???

[structuresguy]

Hi all,

I am looking at an existing building which references ACI 318-51 concrete code. THe drawings (produced in 1958) call for 20 ksi rebar per ASTM A305. I can't get a copy of this standard, as it is withdrawn. Does any know whether the 20 ksi steel is ultimate, yeild, or allowable stress. I know very little about the old ACI code, and only know of 40 and 60 ksi rebar, so any help is appreciated.

Thanks

 

[Qshake]

For evaluating the condition of bridges, the FHWA allows the following as a general rule.

Allowable unit stress range from 18 to 25 ksi and are assumed to be Fy = 40 ksi. The range is for inventory, posting or operating. I didn't think listing them was appropriate for your case so I just gave the range.

Also, it might be advantageous to have a mill test of the material if it is critical.

Regards,
Qshake

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[tincan]

aci 318-63 lists it as allowable stress for working stress design (i saved my old books) never know when they will come in handy.

best tincan

 

[structuresguy]

tincan: great thanks. I suspected it was allowable stress, but couldnt be sure. I know what you mean about keeping old books. I am always on the lookout for old codes to add to my collection. Seems like all you old timers (no offense) are hording your ACI books though....

THanks again