Rods for rebar ?

[Smallfry]

I will soon be wanting to make some 6 metre long rebar cages for ground beams in a raft foundation, using 10mm hoops, and 12 and 16mm longitudinals

I would normally just use cable ties, but these will be craned into place, so I don't want them wibbly wobbly.

So, which rods ? 6011, 6012, 6013, or 7018s ?

I have got a boxful of 6011s @ 3.25mm, but are they up to it ?

Thank you

 

[BrokenBiker]

Whole world of liability issues arise when lifting something that hasn't got certified lifting points...so that means you will be using slings or chains in a basket or single choke configuration to eliminate the structure carrying any load...which means properly tied rebar joints will be more than fine...if you have any worry about the stability of the cage, use extra ties or chuck a strap around it when the slings are on to prevent any movement during the lift.

 

[Smallfry]

Whole world of liability issues arise when lifting something that hasn't got certified lifting points...so that means you will be using slings or chains in a basket or single choke configuration to eliminate the structure carrying any load...which means properly tied rebar joints will be more than fine...if you have any worry about the stability of the cage, use extra ties or chuck a strap around it when the slings are on to prevent any movement during the lift.

I understand your concerns being a lifting pro, but this is NOT any sort of professional undertaking.

It is in our own garden, using our own machine.. Much easier and less risky than trying to manhandle it on my own.

 

[TEO]

Would the wire ties give you the security you're looking for? Also gives you the opportunity to buy a specialist tying twisting tool that'll be redundant ever after but why fly in the face of tradition?

 

[Beanwood]

Keep going @Smallfry - you may yet get an answer that involves welding!

 

[Erie Fred]

I have found that only 7018 works, such that it doesn't crack when stressed.
6011 & even 7104 (Gasp!) will not make a deposit that will hold tight when bent
even slightly.

YMMV

 

[indykid]

I thought rebar was alloy steel. Does welding introduce local hardening or brittleness?

Tying wire would mitigate that risk. Can you chuck some diagonals in to make it less floppy?

 

[premmington]

I thought rebar was alloy steel. Does welding introduce local hardening or brittleness?

Tying wire would mitigate that risk. Can you chuck some diagonals in to make it less floppy?

Welding rebar makes the joint brittle - due to heat treatment - rebar needs to be ductile. There is specific type rebar that can be welded though.

B500B and B500C - might be weldable...?

B500DWR is weldable with LO/HI's

I have tacked rebar together in the past with 7018's burried it in concrete and never had a problem - I could see...

 

[Dcal]

A lot of rebar cages are welded to mitigate the chance of a tied cage collapsing when it is lifted, which has happened and has resulted in fatalities.

A lot of Chinese rebar that was alloyed with boron flooded the European market and caused huge problems about 10 years ago. That problem has largely disappeared now.

Many companies will not lift a rebar cage unless it is welded, however there will be a qualified welding procedure in place for the welds.
The normal process will be MAG with solid wire.

In a home environment I'd use 7018 rods and lay down good hot welds, don't be tempted to think small tacks will be better, they will be more likely to crack.

BS EN ISO 17660-2 is worth a read.

 

[Smallfry]

Would the wire ties give you the security you're looking for? Also gives you the opportunity to buy a specialist tying twisting tool that'll be redundant ever after but why fly in the face of tradition?

Wire ties are OK for doing things in situ I have found, as are cable ties, but not for anything that need moving around.

If you would like to buy one of those tying machines, I could test it for you, but they are out of my pensioners budget

 

[Smallfry]

I thought rebar was alloy steel. Does welding introduce local hardening or brittleness?

Tying wire would mitigate that risk. Can you chuck some diagonals in to make it less floppy?

I will be doing that anyway, even if I weld it.

Seems that all commercially supplied cages are welded.

 

[TEO]

Wire ties are OK for doing things in situ I have found, as are cable ties, but not for anything that need moving around.

If you would like to buy one of those tying machines, I could test it for you, but they are out of my pensioners budget

I take your point about moving a rebar cage, not something I've ever had to do.
Re: machines, powered ones aren't in my budget either. I was thinking of one of the manual twisty ones, they seem to be really efficient.

 

[Agroshield]

UK CARES is the certifying authority for reinfocing steel. They have a guide.

https://www.carescertification.com/content/HtmlContent/8f1c1746-f707-4485-882f-b6ffd23de879/10ea5744-87bc-40f2-9bec-7b284f492b5e/Part%208%20%E2%80%93%20Welding%20of%20reinforcing%20steels.pdf

ISO 17660-1 is here:

BS en 17660-1 - 2008 - PDFCOFFEE.COM

...

pdfcoffee.com

I could not see anything specifying the electrode to be used, but everywhere I have worked, 7018 was used.

The US code is here:

https://www.academia.edu/92545327/AWS_D1_4_D1_4M (type 'academia downloader' into your google to obtain the pdf).

Section 7 just says 'low hydrogen'.