Not What I Meant By Reinforced Rebar
Submitted by: Salvador, Bahia, Brazil via Submit a Kludge!
Favorite Comment: Fixer Bridge says, “I love how the solution to a breaking concrete pole is to support it with a two by four. That’s like patching a hole in a battleship with cardboard; sure, it works for now, but as soon as it gets wet….”
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Whoa… that’s, um… whoa. 80
Trying that smiley again:
Actually, 80 was right. If you meant miles per hour.
Yeah, no doubt
The clearly exemplifies a basic principle of a good kludge:
“The fix must always be of lower quality, durability, and practicality than the object or situation it should be fixing.”
or such total overkill as to render the kludged object useless.
You can’t see how tall the concrete poat is but it’s got to be holding power lines or a sign (because it’s next to a curb). This is truely an accident waiting to happen.
I think the wait is over.
does that post have a cement core?
concrete, maybe… but not cement.
Cement is just a bonding agent used in concrete. Cement alone is very weak. Concrete is a mixture of stones sand and cement. Concrete is very strong, but it is not at all flexible. Adding steel reinforcements to the concrete adds strength and a little flexibility.
There is no “core” to that post. The post is made of steel reinforced concrete. The rusty looking parts are the reinforcement bars or “re-bar.” The re-bar itself is not reinforced with anything, it is the reinforcement. So, the caption is a bit misleading/uninformed.
Sorry if I’m a bit lecture-ish here, but reading the caption was like hearing nails on a chalk board to me, and I just had to do something.
Thanks for the concrete information on cement!
This really cemented my knowledge of the topic.
Hey, I don’t think you have the correct mindset. You are teaching us something useful, and that just won’t fly.
Yes, the term reinforced rebar is incorrect here.
The pole is reinforced concrete, concrete being the base material, and the rebar(reinforcing bar) reinforcing the concrete (hence reinforced concrete).
Concrete is very good with compression forces, as the steel rebar are very good with tensile forces. This is why they are used together, and both material (concrete and steel) have similar thermal expansion coefficients, so concrete and rebar is a match made in heaven.
Now, if the author really meant reinforced rebar, those would be called stirrup i think. stirrups are thin, wire-like steel strips that tie the rebar together.
So bottom line, the stirrup holds the rebar together, and the rebar holds the concrete together under tensile(tension) loads
Now that’s some concrete evidence we all can attest is correct.
I wouldn’t say a match made in heaven…. as time passes the rebar will rust inside the concrete and expand. This will eventually crack the concrete from the inside out.
that really cemen…oh – wait – damn…
Concrete Street Post felt her knees go weak when hearing about the sad demise of her children, Parking post and Highway Guardrail.
Two by four trys to comfort her…
Happy birthday dear post, my brother -hic.
If you thought this was bad, the other side is reinforced with Caution tape.
Caution tape doesn’t actually reinforce… Oh, never mind.
I’m wondering how the pole didn’t completely collapse in the first place?
This actually happens a lot with reinforced concrete. You see it in war or demolition zones. The slab of concrete breaks and a section falls and all is left is the rebar holding the pieces together, which it does quite well. If you are then wondering why concrete at all if rebar is enough. Well, for one rebar alone doesn’t stop wind that well. Also, the fact that it stays together doesn’t mean it holds the shape you want it to.
The wooden post and the top of the Concrete Pole isn’t whats shifted. Just the bottom is. The wooden post has always been there. One of the worms from Tremors hit the bottom and shifted it out of wack. Kevin Bacon is right around the corner somewheres wearing a cowboy hat doing a flash dance to foot-loose to get its attention.
One word..Graboids!!!
Or…Snakeoids! Yeah, that’s it, Snakeoids!
GOOD OLD EGG SHEN….
Now if all it takes is a 2×4, why did they bother with reinforced concrete in the first place?
Reinforced concrete was the kludge for termites!
looks like something brasilians will do lol, and if the pole is one meter away from the curb, you have to pay for it, i feel bad for the person rsrs.
I love how the solution to a breaking concrete pole is to support it with a two by four. That’s like patching a hole in a battleship with cardboard; sure, it works for now, but as soon as it gets wet….
Good analogy! I loved it!
Cardboard’s out, no cardboard derivatives, no paper…
That’s not a 2×4
It’s a space station
Salvador Brazil, Salvador Dali… close enough anyway.
Seriously. If whatever happened to that thing was strong enough to break concrete and bend metal, what makes them think that a piece of wood is going to support it any better?
Wood is VERY strong when it’s standing on end like that. It’s not meant to be permanent though. That’s just a patch until they can get around to fixing it for realz.
Oh, but this 2 X 4 is SPECIAL. It’s a grade D twice-used 2 X 4! No wonder it was used. It’s probably a unique mahoghany hardwood from the Brazilian rainforest that was cut down to help warm the planet.
This post is ~10 meters tall and it’s holding electrical lines, as usual in Brazil.
I hope the guys at my local county building inspections offices don’t see this. This will reinforce their theory that wood is stronger than concrete.
We’ve built two homes with Insulated Concrete Forms and boy oh boy we’ve dealt with some crazy stuff the inspectors come up with.
Couldn’t Jackie Chan have practised on something else?
I live in Salvador and I’ve seen a utility pole like this, _without_ the support. I guess they figured the power lines would hold it in place. Fwiw, which isn’t much, that ’2×4′ is most likely a kind of wood called massaranduba which is super dense and strong and impervious to termites. NOT adequate to support a utility pole obviously… especially with those pathetic metal clamps
BTW that isn’t really a 2×4 it looks more like it has a 3×6 dimension to it. So it would be thicker and stronger. But still not better than a proper concrete post.
For what little it’s worth, you have to define what sort of stronger we’re talking about. In compression, reinforced concrete is very strong. Under tension/torsion the only part of the reinforced concrete that has any strength is the rebar.
In this particular instance, I’m guessing that the rebar is more than strong enough alone to support the post above it in a vertical direction, but won’t stop it falling over. The wood is probably substituting for the missing concrete to hold the post upright.
Oh, and as for why concrete instead of wood if the wood’s stronger: because a) wood’s more expensive and b) reinforced concrete comes in any length you want, but wood doesn’t.
The wood is helping to support the pole, now that the chunk of concrete is gone. That section of the pole was pure rebar, so the wood is reinforcing the rebar.
This sort of picture is a reoccurring theme here. Utility pole is damaged in accident. Broken utility pole is supported primarily by the wires. To avoid secondary damage and to reduce the stress on the wires and the poles up and down the line, the pole is temporarily held in place. If the pole totally disconnects at the bottom, it can do quite a bit of damage in high winds. Pictures of the temporary restraint end up here.
Utility poles are designed to be in service for a century or more. Sometimes a temporary repair is left in place for a few years. That is still temporary in the life of the utility pole.
wellllllll… if you know bahia you would know it is wet everyday…
thats a place of shit.. shit people.. shit weather
hate there
After reading all of these posts I can now say that I know waaaaay to much about concrete posts.
Actually in that particular application re-bar is not used. What is used however is a wire mesh type ring which then goes into a mold and the concrete is then poured around it forming the pole. Re-bar is actually metal rods not a wire net or what some refer to as “hog wire”. And since the net is now bend that is putting enormous stress on the basic structure. The 3×6 board placed on the pole and “U” clamped is fairly common actually. And you can still see the chunks on concrete on the back of the wire that will come off as it is broken up as well. You see this often enough in rural areas.
Hey your right that is a wire mesh not rebar. Also there’s is a seam so it must also must be a mold. In that case the mesh i9s made and ste down in the mold with spacers to raise the mesh up off of the mold surface and them the mold is assembled. I ma presuming then that they pump the cement into the mold(I don’t see no rocks in the pole)maybe in a dry cast or a low slump system.
Then on another guess they steam the mold to cure and harden the post.
Uh……I used to work in a concrete product manufacturing plant if your wondering.
I bet the car that HIT that post has a big dent in it.
Probably has that wrap around look.
Cheers to Brasil, they are practically brothers to Russians there
brothers of russians?? it´s in south america!
This title should say ‘reinforced concrete’ Rebar IS the the reinforcement…. not the thing being reinforced.
-Dave, the nit-picky civil engineer.
The rebar is being reinforced by the wood post since the concrete is essentially gone.
Hi, Dave
Because, two-by-fours need love too.