Yesterday's Tractor Co.
Shop Now View Cart
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile    Log inLog in 

Wire rebar in concrete forms or not?

Goto page 1, 2  Next

 
Post new topic    
View previous topic :: View next topic  
Author Message
Stan in Oly, WA
Tractor Guru


Joined: 08 May 2005
Posts: 3751


Report to Moderator

PostPosted: Sun Apr 15, 2018 10:14 pm    Post subject: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Someone I consider knowledgeable on the subject of building concrete walls told me something I?d never heard before. We were talking about placing rebar in concrete forms. He said that where horizontal lengths of rebar overlap, it?s better if they aren?t wired together. He claimed that wiring rebar together in the forms is only to keep it from being moved out of position when the concrete is poured over it. In places where there is no danger of the rebar being moved by the concrete, the pour will be stronger when the pieces of rebar are not wired together than when they are. My first response was to reject this, but after giving it some thought I realized that I don?t actually know enough about it to have an educated opinion either way. I can?t honestly say that I have an educated reason for the way I pour concrete other than it?s the way I?ve always done it because it?s the way I?ve always seen it done. But I?m largely self-taught, and the small contractors I?ve worked with have also been largely self-taught, so maybe the only basis I have for the way I do it is habit. I wouldn?t mind being set straight, even though I hope I don?t have to pour much more concrete in this lifetime.

Stan
 
Back to top
View user's profile
Stephen Newell
Tractor Guru


Joined: 11 Jun 2011
Posts: 6130


Report to Moderator

PostPosted: Mon Apr 16, 2018 1:42 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

I agree, if the rebar is where it won't move it's unnecessary to wire it together. Having said that though rebar easily moves from the weight of concrete so I usually wire it all together. I'd rather spend the time wiring it together than have to watch it while making a pour and perhaps have to fight it back in place if it does move.
 
Back to top
View user's profile
MarkB_MI
Tractor Guru


Joined: 29 Aug 2004
Posts: 11272


Report to Moderator

PostPosted: Mon Apr 16, 2018 2:10 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Well, wiring the rebar together certainly won't make the concrete any stronger; there's no way a few wraps of wire will be able transmit any tension force between two pieces of rebar. I don't think I'd go so far as to say it makes the structure significantly weaker, though.
 
Back to top
View user's profile
Billy NY
Tractor Guru


Joined: 05 Mar 2009
Posts: 7135
Location: NY

Report to Moderator

PostPosted: Mon Apr 16, 2018 3:20 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

I would disagree based on details on structural plans of buildings I have constructed, and would reject on the same basis as you have initially stated. Why ? Don't know, interesting question though.

Below links might be of interest.
CRSI Reinforcing Bar Placing

BN Products

 
Back to top
View user's profile
Russ from MN
Tractor Guru


Joined: 11 Feb 2006
Posts: 7635
Location: N MN

Report to Moderator

PostPosted: Mon Apr 16, 2018 4:21 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

I was an industrial construction carpenter for 5 years so I saw a lot of rebar, and it was always wired together, and there are specifications for for minimum overlap. The placement of the rebar is very important and if it's not wired together it may get pushed out of place by the pour. Rebar is supposed to be in the area of tension, it does very little good in a compression zone. Precast beams have to be handled very carefully as they are only deigned to be strong in one direction, I suspect the recent bridge collapse in FL was due to mis-handling.
 
Back to top
View user's profile
WGM
Tractor Expert


Joined: 11 Sep 2004
Posts: 2534


Report to Moderator

PostPosted: Mon Apr 16, 2018 5:19 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Wiring is used to keep the bars in the proper position during concrete placement. Wiring itself adds very little to strength.
 
Back to top
View user's profile
PJH
Tractor Guru


Joined: 26 Apr 2009
Posts: 5158


Report to Moderator

PostPosted: Mon Apr 16, 2018 5:34 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Stan, it's been a while since I've had the book open, but I can assure you that the Standard Specifications for Road and Bridge Construction specify that rebar splices WILL be wire tied - twice on each splice, if my memory serves me correctly. When you're loading wall forms with concrete, a loose bar can cause you much grief.

On your own work, you can do it as you please, of course.
 
Back to top
View user's profile
David G
Tractor Guru


Joined: 11 Jan 2008
Posts: 21378


Report to Moderator

PostPosted: Mon Apr 16, 2018 5:50 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

I have always seen it tied, and would assume there is a standard for how much overlap on the rebar too.
 
Back to top
View user's profile
Steve@Advance
Tractor Guru


Joined: 12 Nov 2013
Posts: 11196


Report to Moderator

PostPosted: Mon Apr 16, 2018 7:11 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Ever road construction job I've seen always has some workers bent over, hand tying rebar...

So it must be a necessity.

I can't imagine how a human body can take that day after day!
 
Back to top
View user's profile
PJH
Tractor Guru


Joined: 26 Apr 2009
Posts: 5158


Report to Moderator

PostPosted: Mon Apr 16, 2018 7:20 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Just keeping the hard hat on is a pain. Gotta cinch it up tight.

Ironworkers are a tough bunch.
 
Back to top
View user's profile
oldseabee
Regular


Joined: 07 May 2016
Posts: 73


Report to Moderator

PostPosted: Mon Apr 16, 2018 8:25 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

CVPost-David G wrote:
(quoted from post at 06:50:23 04/16/1Cool I have always seen it tied, and would assume there is a standard for how much overlap on the rebar too.


Like said, tying it just holds it from moving while poring the concrete. On the bigger re-bar we welded it. The rule we used for lapping was 30 X the diameter.
 
Back to top
View user's profile
Mule Meat
Regular


Joined: 14 Jul 2016
Posts: 477


Report to Moderator

PostPosted: Mon Apr 16, 2018 9:22 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

In recent years I have not saw anyone tie rebar when pouring a wall. They have all used cross ties (either plastic or metel) that the rebar snaps into.

When a company poured a long driveway around part of a apartment complex last year. The forming machine they used "injected" the rebar automatically as it poured, formed and finishsd the drive all in one pass.
 
Back to top
View user's profile
dpendzic
Tractor Expert


Joined: 05 Mar 2009
Posts: 2016
Location: long island NY and Hancock Ma

Report to Moderator

PostPosted: Mon Apr 16, 2018 10:30 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

Concrete specs generally call for rebar splices to be tied together so there is no gap between the pieces, and keeps the rebars from moving. Rebars may be not tied if there is sufficient distance between the rebars that it gets filled with concrete and no voids are created--the distance apart depends on the largest size aggregate in the mix.
 
Back to top
View user's profile
dpendzic
Tractor Expert


Joined: 05 Mar 2009
Posts: 2016
Location: long island NY and Hancock Ma

Report to Moderator

PostPosted: Mon Apr 16, 2018 10:51 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

many precast beams are subjected to negative moment in certain areas, so those beams are reinforced not only on the bottom but also on top. The designer will usually specify the pick up points and storage points to minimize the stresses.
 
Back to top
View user's profile
dpendzic
Tractor Expert


Joined: 05 Mar 2009
Posts: 2016
Location: long island NY and Hancock Ma

Report to Moderator

PostPosted: Mon Apr 16, 2018 10:57 am    Post subject: Re: Wire rebar in concrete forms or not? Reply to specific post Reply with quote

the newer standards take many things into consideration when designing the length of a splice,
the grade of rebar
the stress level in the rebar
% of rebars spliced in any one cross section
strength of the concrete
location of splice (top or bottom of beam)

I have designed splices where I had to use up to 60 times the diameter.
 
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Tool Talk All times are GMT - 8 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  

TRACTOR PARTS TRACTOR MANUALS
Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

YT Home  |  Forums

Modern View Forum powered by phpBB © 2001, 2005 phpBB Group

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters