×
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

Stirrup spacing check

Stirrup spacing check

Stirrup spacing check

(OP)
There are two code requirements that I look at when spacing my stirrups and these are:

s =< 48db, column width, (and one more that I can't remember!)

AND

Maximum spacing: s =< min(600mm, 0.7dv)

What is the difference between both of these checks and why was I told that the second check should not be performed when spacing stirrups in columns? The clause does not mention that the latter check is for beams only, which is why I was left confused when I was told to ignore it when designing stirrups in columns.

Of course, upon asking the question to my supervisor, he responded "I don't have time to explain, just do it." Heh.

Clansman

RE: Stirrup spacing check

(OP)
I might as well ask in this thread: Why are minimum requirements for horizontal rebar on walls higher than the minimum requirement for the vertical spacing of rebar on walls? Just curious.

Clansman

RE: Stirrup spacing check

I think the one you forgot was 16d where d is the diameter of the vertical bars.  I just looked for it in the code, but cannot find it either.  I believe I recall from some long forgotten source that it has something to do with the buckling length of the vertical bars.  If the column ties (not stirrups) are further apart than 16d, the main bars might buckle and fail to carry their expected load.

If you are talking about stirrups in a beam, they have to be spaced closer to avoid a shear failure resulting from a crack falling between the stirrups.

Best regards,

BA

RE: Stirrup spacing check

THE SPECIFICATION OF MAXIMUM SPACING OF STIRRUPS OF 48dT,16DB AND b OR h  whichever is smaller is only for column in ACI code(318) and max. ermitted spacing of d/2 is for beams.The above specifications are apllicable to non-seismic resistant buildings.
   The limit of d/2 is secified because length of shear crack is about 'd' in beams.
   Shear is not critical in columns beacuse shear strength of members increases considerably in presence of axial comressive force.

RE: Stirrup spacing check

I agree, except shear CAN control in a column on occasion, and then you actually need to design the ties as stirrups (and the spacing will be less than d/2).

Horizontal reinforcement in a wall is heavier than vertical reinforcement, because a wall is much longer parallel to the horizontal bars.  The bars are for crack control.

DaveAtkins

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