Minimum Yield Stress & Concrete Compression strength allowed in ACI code 1

[XinLok]

Is there a minimum and maximum values for Yield Stress fy and Concrete Compression strength f'c in ACI code?

for example, is it allowed to use f'c as 2000 psi in concrete column?
or is it allowed to use rebars with fy = 150000 psi in foundation?

 

[msquared48]

For f’c it depends on you local conditions. Where I am, it varies from 2500 to 4000 psi. But I can see some farming jurisdictions still allowing 2000 psi.

As for the reinforcing steel, 40 ksi -never used any less.

Mike McCann, PE, SE (WA, HI)

 

[phamENG]

There aren't necessarily minimum or maximum values in an absolute sense, but the design equations do change as you move through the spectrum, and there are restrictions based on certain criteria.

For instance, freeze/thaw or harsh soil chemistry will require higher f'c (and the IBC does have minimums based on geography).

If you want to go high on f'c, your beta factor (usually 0.85) will start to drop as f'c goes over 4000psi.

For rebar, I think there are some modifications/restrictions for use but I don't remember them off hand.

 

[JAE]

For concrete strength look at ACI 318-11 - section 1.1. Min. f'c is 2,500 psi. No maximum limit is applicable unless limited by a specific code provision.

For reinforcement - Section 3.5.3 dictates many ASTM specifications that are acceptable. If your steel meets these, you are OK.

In the section on development of reinforcement there is some commentary on concrete with strengths >15,000 psi. See section 12.2.4.
See 12.6 for a limit on steel fy.

There may be others.

 

[r13]

Two factors affect the choosing of concrete materials the most are: "practical, economical and meeting code requirements". When I started as a designer, we considered concrete compressive strength of 1500 psi a structural grade concrete, and at then the reinforcing was grade 40 steel. I don't think you can find either in the market nowadays (a practical concerns). When you using 150 ksi steel in your foundation, what goals you want to achieve? The likelihood is you'll never achieve saving, as most foundations are governed by minimum reinforcing (an economical concern); and you tend to violate the basic of reinforced concrete design - steel yield just prior to compressive failure of the concrete (a code requirement). Leave material selection to a structural engineer, or learn by practices with advices from a senior engineer.