×
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

Large Radius Rebar Bend

Large Radius Rebar Bend

Large Radius Rebar Bend

(OP)
Say I was to design a beam or slab with a long arched or cambered simply supported span.  At what radius would the flexural rebar need to be mechanically curved?  Are there any prescriptive requirements for placing flexural rebar in a curved manner as opposed to straight/flat?  That is, can you simply use the self-weight of the rebar to deflect itself into position atop an arched form?

 

RE: Large Radius Rebar Bend

I don't see why not.

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Large Radius Rebar Bend

CRSI Placing Reinforcing Bars (8th Ed.) states in part, "The proper tying of reinforcing bars is essential in order to maintain their position during work done by other trades and during concrete placement."  
ACI 318 states that rebar is to be tied and supported sufficiently to maintain its position during placement of concrete, but I do not have that reference in front of me.

Deflection would depend on the bar sizes and lengths, stirrup configuration, and a host of other unpredictable factors as concrete is placed.  You could use gravity to deflect the bars, but they need to be tied and supported in that position.

John Turner CSP PE
CRSI Greater Southwestern Regional Manager

RE: Large Radius Rebar Bend

Wouldn't you want to camber the span so it creates a nett hog and if so how would detailing reinforcement with a "sag" properly reinforce the span.

Second point, the bar may deform when spanning between supports. But when the concrete is placed and vibrated, can you be sure that the reinforcement maintains it curvature.  

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