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1. dmckeo+(OP)[view] [source] 2021-05-25 21:58:36
No mention of epoxy coatings for steel rebar? Look for green-coated rebar as you pass highway construction sites.
replies(5): >>quickt+N >>ddkto+o1 >>chairm+E1 >>Xamayo+o2 >>brohee+h3
2. quickt+N[view] [source] 2021-05-25 22:03:55
>>dmckeo+(OP)
There’s also hot-dip galvanized and stainless steel rebar.
replies(1): >>rsync+K2
3. ddkto+o1[view] [source] 2021-05-25 22:08:42
>>dmckeo+(OP)
Epoxy coating is falling out of favour, as it has two downsides: 1) is has a weaker bond to the concrete, so you need longer bars to transfer the force, and 2) if it gets damaged (scratched or cut), the corrosion will concentrate at that location, and you are more likely to end up with a fully rusted-through bar, as opposed to a small amount of corrosion spread over the whole bar.

Reinforced concrete is much like clothing: a stitch in time saves nine. With regular cleaning and maintenance, it can last much longer than if you just let it deteriorate.

4. chairm+E1[view] [source] 2021-05-25 22:10:23
>>dmckeo+(OP)
For some reason I stumbled across a wild YouTube channel by a guy named Tyler Ley that is “crazy for concrete”. If I remember correctly he’s a civil engineering professor and has a lot of fascinating videos about concrete.

In particular one about epoxy coated rebar that gives interesting notes about why it has its problems: https://youtu.be/xVDy84rR5Z8

I had a great couple of days learning all about the complexities of concrete through his videos.

replies(1): >>anitil+7o
5. Xamayo+o2[view] [source] 2021-05-25 22:15:11
>>dmckeo+(OP)
That certainly helps, but in some cases such as when the rebar is under tension the epoxy coating can result in unexpected failure if there is any damage to it. The small areas lacking coating are corroded more aggressively, resulting in deep pitting which can weaken the bar to the point of failure.
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6. rsync+K2[view] [source] [discussion] 2021-05-25 22:17:29
>>quickt+N
... with stainless being a much better (but much more expensive) choice.

HD Galvanized is a coating whereas stainless steel is a different material - it is stainless all the way through ...

replies(1): >>sgtnoo+S8
7. brohee+h3[view] [source] 2021-05-25 22:19:32
>>dmckeo+(OP)
It's pretty dependent on skilled people using it, every ding must be properly repainted before the concrete is poured, so extra care must be taken transporting and laying it.

https://www.ijser.org/researchpaper/Epoxy-Coated-Versus-Galv... has a lot more, but clearly not a panacea...

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8. sgtnoo+S8[view] [source] [discussion] 2021-05-25 22:54:17
>>rsync+K2
It's a coating, but my understanding is that it basically creates a battery that keeps the nearby iron from deteriorating. Small gaps in the coating therefore don't really matter as long as there is still some zinc nearby.
replies(1): >>froste+ng
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9. froste+ng[view] [source] [discussion] 2021-05-25 23:44:17
>>sgtnoo+S8
Like zinc anodes on a boat?
replies(1): >>sgtnoo+GV
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10. anitil+7o[view] [source] [discussion] 2021-05-26 00:48:17
>>chairm+E1
He is fantastic! I was really struggling to find his name again.
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11. sgtnoo+GV[view] [source] [discussion] 2021-05-26 05:49:28
>>froste+ng
Yep, I believe that's the same mode of operation. The definition of galvanic is, "relating to or involving electric currents produced by chemical action."
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