×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Amount of Reinforcement

Amount of Reinforcement

Amount of Reinforcement

(OP)
While determining the Rho= Rebar Area / b*d at any given section, do we include sum of both tensile and compressive steel areas to calculate Rho or the equation should only consider the reinforcement for either positive or negative moment while satisfying the section for Rho max and Rho min values?

I typically take sum of areas for both tensile and compressive rebar, just trying to think out loud.

Thanks,

FEM4Structures

RE: Amount of Reinforcement

Tension side only if you are designing singly reinforced beams (which is how most engineers do it). Rarely do we use doubly reinforced beam design methods unless we have to.



RE: Amount of Reinforcement

(OP)
Case is for the walls with active earth pressure on one side. Have vertical rebar resisting negative moments and at others resisting positive moments following PCA Rectangular Tank Coefficients. All concrete checks are satisfied except Rho check if only to consider tensile steel at any given section.

Thanks,

FEM4Structures

RE: Amount of Reinforcement

ρ = As/bd

As is the area of tension steel. You don't add both the tension and compression steel together.

RE: Amount of Reinforcement

I'd put .0033 on both faces, in both directions.
But that's me.

RE: Amount of Reinforcement

You might ask for some help from someone in your office to explain this one to you.

Reinforcement ratio is an extrememly basic, yet crucial, concept.

RE: Amount of Reinforcement

JStephen,

The threads you referenced were about the commingling of the code requirement for flexural reinforcement vs. direct tension shrinkage and temperature reinforcement. Shrinkage reinforcement is based on the gross area of the concrete, and can be placed throughout the section. It is clear in the current thread that the OP is asking about flexural reinforcement, and JAE has given the correct answer...the required amount of flexural reinforcement must be on the tension side.

RE: Amount of Reinforcement

It sounds like two load cases are being designed for; backfill with an empty tank and full tank without backfill. You need to look at both load cases separately to be certain your tension reinforcing meets code requirements.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources