All thread rod as rebar

[Streetcar]

Didn't know you weren't supposed to weld rebar. I thought I'd seen it done on some very large posts/piers on TV. Only done it when making my own concrete railway ties for a retaining wall so I won't worry about it.

Rebar is weldable. welding is used primarily on large diameter bars

 

[Sprinkler Fitter]

When I poured the 40x40 addition on my shop, I used cattle panels which I had on hand after we sold off all the stock for matting. Been in there over 10 years now and no cracks anywhere.

What is matting? To use it as a mat to walk on?

 

[5030]

cattle panels.

 

[Flogger]

Use it. Concrete will adhere to it just fine. I am known as captain overkill and I would not hesitate a second. Most people would be shocked to see what my Great grandfather used for reinforcement in some of the 100 year old concrete around here!!

 

[jigs_n_fixtures]

Rebar is weldable. welding is used primarily on large diameter bars

Some rebar might be weldable, but generally it isn’t. And whether it can be welded would highly dependent on where it is, and where the weld is in relation to the rest of the bar.

 

[5030]

Most rebar in new construction is wire tied together, not welded. Commercially made rebar is the lowest grade of recycled from scrap steel produced today so the chems can be just about anywhere.

 

[jigs_n_fixtures]

What is matting? To use it as a mat to walk on?

A layer of reinforcing steel is referred to as a mat. Depending on the purpose of the structure, and loads it is designed to withstand. A bridge structure may have so many mats, and so much steel in each mat that you have to be carefull of not get teh steel so close together that the larger aggregate in the concrete to pass between the steel.

Ideally reinforcing steel has a slight film of surface rust, not flakey rust but the fine surface rust. The micro-pits of the rust allows the cement paste to adhere more strongly to the steel.

Generally re-steel should be free of paint, oils, or anything else which could interfere with the adhesion of the concrete to the steel. Concrete has plenty of compressive strength, but little tensile strength and the steel is added to add tensile strength combination of concrete and steel.

 

[Cougsfan]

When I was a plant engineer the previous plant ownership had poured a elevated concrete deck in the plant. Before they poured it they apparently raided their bone yard and filled the forms full of old angle iron, pipe. scrap metal, wire and whatever else they could find. Not just a little, but a lot and it was put in in a very random fashion! Years later after we purchased the plant we decided that we had to replace that deck because it had developed a crack and vibrated rather noticeably from the equipment that was mounted on it. It was an obvious problem. We didn't know at that time that was how the deck had been built. When we saw what we had we realized that it was not only a serious safety concern; it was a legal liability as this re-inforcement method doesn't meet code. Demolishing that deck was an absolute nightmare! It had to be jackhammered into very small pieces. Metal had to be repeatedly cut with a cutting torch to remove chunks. It added more that a week to our project schedule. Bottom line; metal doesn't add strength to concrete unless it is put installed in a logical fashion.

 

[milkman636]

I built a steel frame building on poured walls about 18 months ago. The anchor bolts specified on the engineered drawings for each column were basically 12” long pieces of 1/2” threaded rod with a plate washer sandwiched between to heavy hex nuts imbedded 8” down into the foundation wall. A grand total of 60 galvanized threaded rods are holding the 40x60x12 building to the foundation. If the 24 in the picture below can take the shear of a 60’x12’ west facing wall and resist the uplift of the building, I think they are strong enough to reinforce a floor as well. But I’d probably want them galvanized or plated, or research an appropriate primer, and make sure I had the rod solidly embedded and not laying in the bottom of the slab.

 

[Streetcar]

Some rebar might be weldable, but generally it isn’t. And whether it can be welded would highly dependent on where it is, and where the weld is in relation to the rest of the bar.

Standard rebar is weldable. Some specialty rebar may not be weldable.
Loading of bar determines whether it should be welded or not