Pipe in concrete slab, rather than rebar?

[bigtiller]

Rebar is “deformed” which all those little ridges grab the concrete. Pipe woukd be to smooth and to big, my guess it would weaken the slab not make it stronger.

If anyone wants to test that, just pound a 1/2" rebar about a foot into some undisturbed soil and try to pull it out with one hand...it's in there pretty good.

 

[Jstpssng]

Find another use for the pipe!

As pitted as it is, the only other thing it's good for is "scrap". It's still sound, but I wouldn't want it for anything like a flagpole or something else cosmetic.

 

[RalphVa]

We have some old 1 1/2" heat pipe which is somewhat pitted, so not suitable for anything else which I would use it for such as a flagpole. I've been thinking about using it for reinforcement, and am wondering if losing that much concrete would affect the structure. It will just be in a couple of small outbuildings, so not that much harm done if it doesn't work as planned; and definitely better than a gravel floor.

The FIL who was good with cement used to throw all sorts of old iron into his concrete. Could also use bamboo. A famous swimming pool in Florida was made using bamboo. Still there.

 

[crazyal]

Ditching the pipe is a smart choice. Rebar is not the same alloy as pipe. In fact they make a special rebar that's weldable vs the standard stuff that shouldn't be. Rebar doesn't rust like a steel pipe. It does rust but where a steel pipe will rust and start to flake in a short period of time the rebar takes much longer. Rust is a killer for cement. It expands and breaks the cement apart. Even if it doesn't break the cement sooner or later the steel will be converted to all rust which will not have any strength at all.

 

[ArlyA]

Ditching the pipe is a smart choice. Rebar is not the same alloy as pipe. In fact they make a special rebar that's weldable vs the standard stuff that shouldn't be. Rebar doesn't rust like a steel pipe. It does rust but where a steel pipe will rust and start to flake in a short period of time the rebar takes much longer. Rust is a killer for cement. It expands and breaks the cement apart. Even if it doesn't break the cement sooner or later the steel will be converted to all rust which will not have any strength at all.

Oh it does rust. Our state and I know MN state highway departments discontinued the use of bare rebar because of rusting and then it blowing out of road structures due to the swelling. Seems that rebar within 4" of the surface got enough salt to ruin bridges. Today all that rebar is cut to proper lengths and painted before it goes to job sites.

 

[KennyG]

Steel in general will not rust if it is encased in concrete. The chemistry in concrete prevents rust. If the concrete cracks or has a void, it can rust. The problem with the highway structures was probably excessive cracking that allow intrusion of water and salt. For walls and covered slabs, the rebar will never have a rust issue.

 

[ArlyA]

Steel in general will not rust if it is encased in concrete. The chemistry in concrete prevents rust. If the concrete cracks or has a void, it can rust. The problem with the highway structures was probably excessive cracking that allow intrusion of water and salt. For walls and covered slabs, the rebar will never have a rust issue.

Please let the various states department of transportation who today require coated rebar, know this.

 

[fried1765]

Please let the various states department of transportation who today require coated rebar, know this.

KennyG lives in SW. Michigan, but you live in N. Michigan.
Major climate difference for re-bar corrosion!

 

[KennyG]

Here is an article on coated rebar. The first paragraph has the important information. The concrete forms a protective coating on the rebar. Unless it is disturbed by chloride or other contaminant intrusion, it will not corrode. I can understand why coated rebar would be used on highways or bridges. However, if you are pouring a building slab or wall, etc. it will not be needed.

I once had to prove to the US Nuclear Regulatory Commission that hidden corrosion on steel plates was only caused by a void and defect in the concrete and would not exist in other locations.

STRUCTURE magazine | Steel Rebar Coatings for Concrete Structures

 

[Industrial Toys]

A sister of my Fathers employer for many year (Harris Rebar) pionnered the Epoxycoat process. Now I'm seeing that it may have huge shortcomings as far as the EPOXY staying on. Basicaly a lot of thought protected structures may not be. Kind of like buying a powder coated trailer, maybe! lol

I have put plenty of scrap in concrete. If rod, then bend the ends over or in loops. I don't think you could be any further off base wanting to use pipe. Rebar is high tensile and doesn't occupy the space of pipe.