×
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

Concrete Rebar Shop Drawings

Concrete Rebar Shop Drawings

Concrete Rebar Shop Drawings

(OP)
Does any body else have trouble getting detailers to provide rebar clear covers, etc. on their placement drawings? If so, does anyone have a "scary" CA note that they find useful to place on the shop dwg review pdfs? This is one of the most annoying peeves of mine. Devil's advocate: Maybe it shouldn't be?

RE: Concrete Rebar Shop Drawings

I've never asked them to. It's clearly stated in the structural drawings.

RE: Concrete Rebar Shop Drawings

(OP)
It *is* in the structural drawings, but I do not view the CD's as placement drawings for rebar. I just could never envision a worker locating piece marks on the rebar drawings and then flipping to the CD's to find clear cover requirements.

RE: Concrete Rebar Shop Drawings

Jay...when is the last time you've seen a rod buster with a set of structural drawings in their hand? I honestly don't think I ever have. Placing drawings should be a stand alone set of drawings for placing rebar. This thinking follows ACI and CRSI recommendations also, I believe.

Stamp them 'revise and resubmit' until the clearances are shown..?

RE: Concrete Rebar Shop Drawings

its funny. My experience is 50/50 whether they've got rebar shops, or structural drawings in their hands. Rarely do they have both.

RE: Concrete Rebar Shop Drawings

(OP)
One thing is known for sure, and that is the CD's do not have piece marks. I don't know how they would get by without looking at only the Cd's.

RE: Concrete Rebar Shop Drawings

MacGruber22:
What does a “scary” California (CA) note have to do with anything? How about, “Reinforcing shop drawings which do not show clear cover to rebar will not be accepted for review and acceptance for construction.” This note as part of you general notes on concrete, on your plans, or in the specs. Maybe people don’t understand your notes because you use acronyms which no one can interpret. When the reader needs to spend more time interpreting, looking up possible meanings of acronyms, than it would have taken you to type it out, that may be a communication not communicated.

RE: Concrete Rebar Shop Drawings

who ever said that steel reinforcement "shop" drawings were "placement" drawings? they are done by the fabricator for use in fabricating the steel in the shop, not for forming or placing it. In order to get the bar lengths correct, the required cover does need to be considered, but not necessarily shown on the shops. the contractor had better have the CD's on the job site...

RE: Concrete Rebar Shop Drawings

Most Rebar shops I see have a nice big fat note that says they are not stand alone drawings, or placement drawings. They are to be used in conjunction with the structural drawings.

RE: Concrete Rebar Shop Drawings

(OP)
dhenger - acronyms are not the issue here. And, no need to extrapolate my use of "CA" in the thread to my drawings - I do not use abbreviations on my drawings unless they are defined on the drawings. My specs specifically require rebar shop drawings to indicate bar cover, among all else. No matter how many notes or spec lines call my requirement out, I always get resistance - sometimes I get tired of prolonging the shop dwg process and accept them anyways, with the hope they will use the CD's in conjunction.

cvg: I do in my specifications.

Quote:

who ever said that steel reinforcement "shop" drawings were "placement" drawings? they are done by the fabricator for use in fabricating the steel in the shop, not for forming or placing it.

Are you telling me that piece marks are not used in the field for placing bend bar? What *are* the placement drawings, then? Some combination of the detailer's and Cd's?

These are the bundles of bars they are going to get in the field with tags on them indicating the piece marks, right? What drawings do they absolutely need to place these bars...the detailing drawings with the piece marks on them, hence placement drawings. If the bundles didn't have the piece marks they would be wasting time measuring the pieces and correlating them with the CD's. I just don't see how else this could be properly performed.

RE: Concrete Rebar Shop Drawings

(OP)
oop. it was meant to be "cover my a$$" notes. Typing too fast!

RE: Concrete Rebar Shop Drawings

I will add a note regarding cover to the shops. Before the first slab pour, I make sure that I am out there. Before they start laying the rebar, I tell them that I need to see 3 things:


* The bar orientation must match the plan (inner / outer layer)
* The rebar cover is correct 3/4" on top, more is not better
* I want to talk to the rebar inspector to make sure that he has both a set of structural drawings and approved shop drawings. I tell him / her to check both and call me with questions.

More often than not, the top rebar cover on elevated slabs is way too low.

RE: Concrete Rebar Shop Drawings

(OP)
Thanks, manstrom. That last remark is always concerning in two-way structural slabs - selective demolition often reveals too much cover.

Part B of the ACI 315-99 *seems* clear to me that one of the detailer's responsibilities is bar placement drawings. I wonder how many detailers accept that as true.

RE: Concrete Rebar Shop Drawings

The definition of "rebar shops" and "placing drawings" is different in different parts of the country. As an industry, we are working to improve placing drawings. I am hopeful that we will eventually manage to get full placement information, uniformly, on the placing drawings, but this will probably require better checking by the structural and contractor communities. ACI 301 will implement a few changes in the 2014 edition, and CRSI is also working to help define what is provided and used by the fabricators and placers. Obviously, the goal is to assure that the design is properly constructed.

RE: Concrete Rebar Shop Drawings

There are other ways of doing it. I know that most of you are talking about US practice, but in Australia, placement drawings are rarely used. The bar schedules are shown on A4 sheets, with full descriptions of where the bars go, and chairs are provided to get the right height. The structural drawings are used for control. It works, most of the time.

RE: Concrete Rebar Shop Drawings

Hokie66,

What is an A4 sheet?

RE: Concrete Rebar Shop Drawings

An A4 is what the rest of the planet calls an 8.5"x11" sized sheet of paper.

RE: Concrete Rebar Shop Drawings

except that it is a different size...

A4 measures 297mm x 210mm (29.7cm x 21cm).

RE: Concrete Rebar Shop Drawings

That's 11.7" x 8.3". Not enough to notice, but enough to cause problems with scanning and printing.

RE: Concrete Rebar Shop Drawings

Showing the cover and basic dimentions of the concrete could be useful to the fabricator as a double check on the bar lengths.

At first I though CA stood for California as in maybe Caltrans is known to have good strong construction notes.

RE: Concrete Rebar Shop Drawings

(OP)

Quote (graybeach)

Showing the cover and basic dimentions of the concrete could be useful to the fabricator as a double check on the bar lengths.

I agree - it also useful for the detailer.

hokie66, that is interesting - and somewhat of a reasonable approach.

Thanks, everyone.

RE: Concrete Rebar Shop Drawings


I have found some rebar detailers who DO indicate the cover requirements - but it's not consistent and may vary from detailer to detailer.

IMHO rebar drawings are intended to serve 3 distinct and separate purposes:
#1 - Demonstrate the detailer's interpretation of the contract drawings with respect to bar sizes, arrangement, splices, etc.
#2 - Determine the bar quantities, dimensions and bend details for their fabrication.
#3 - Provide the means by which the installer can identify which bar goes where.

The engineer of record is obligated to confirm #1 in his/her review of the rebar drawings.
The fabricator is obligated to cut/bend bars in accordance with #2.
The installer is obligated to install the bars in accordance with BOTH the contract drawings and the rebar drawings. Realistically, the latter should carry more weight as changes are often made in the review process that will never be reflected in updated contract drawings.

Ralph
Structures Consulting
Northeast USA

RE: Concrete Rebar Shop Drawings

(OP)
Thank you for your imput, RHTPE!

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