huangyhg

rebar strength in 1958???
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 i can't get a copy of this standard, as it is withdrawn.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
check out our whitepaper library.
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
eng-tips forums:real solutions for real problems really quick.
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
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

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