ACI 318-63 What is the allowable compressive strength of plain concrete for WSD

[adk48ist]

I am designing a CSM wall. we are using Plain Concrete provisions as there is no codes for Cutter Soil Mix walls.

I am using working stress design, to get a safety factor for applied stress over allowable stress.

I need to find the allowable compressive strength of plain concrete

I see factors of 0.6 and 0.45 and even 0.33 times f'c, but no solid reference

Mostly papers I can find on the net. I don't have a copy of 63 code.

I am sure they have it there.

If anyone can help , I will be grateful

Thanks

A. D. Ketin

 

[BUGGAR]

Way back then 2500 psi (wsd) was a pretty common mix. Highway concrete was 3000 psi. I think prestressed (yes, we had it then) was 5000 psi.
What's a cutter soil mix? Is that a soil-cement mix?

 

[KootK]

Here's 318-63: Link. My 1952 CRSI manual mentions a lot of 3000 psi concrete.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[dcarr82775]

App A of 318-89 had the working stress values. It says to use 40% of the ultimate capacity obtained from Chp 10. Chp 14 for walls.

 

[adk48ist]

Thank you guys.

Buggar, Yes it is soil-cement mix. Based on test results 900 to 1000 psi is used for f'c.

I needed the allowable for working stress design so I can calculate the safety factor,but as dcarr82775 suggests
factors 0.4 or 0.45 is used for f'c to get that WSD allowable. I don't have 89 code but try to find it to see.

thanks again

Alan

A. D. Ketin

 

[adk48ist]

kootk

I couldn't access that link at work..Somehow it is restricted...Can you write the web address so I can go directly there,
or use VPN client to get around it.

Thanks

Alan

A. D. Ketin

 

[KootK]

It may be that I never should have attempted to share that document in the first place Alan. Dropbox is smart that way somehow. I had assumed that, because of the age of the document, it was public domain.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[dcarr82775]

Not 40% of f'c. Calculate Phi Pn per chapter 10 and take 40% of that as your allowable. The 89 version used the old 1.4D / 1.7L factors, and phi of 0.75 and 0.70 for spiral and tied columns. Other than that the axial capacity equation has not changed. 318-89 notes to use a Phi of 1.0 for walls designed per chapter 14