An average day

[ICE]

Rick,

I would start with why the plans don't show any steel. Beyond that, if the steel is not required and that's why it's not on the plans, how could it be wrong?

The only mistake worth fixing that comes to mind would be if the steel was susceptible to rusting. And only because rusting steel can crack concrete.

I wonder if your's was a trick question.

 

[fireguy]

Rick, The only mistake worth fixing that comes to mind would be if the steel was susceptible to rusting. And only because rusting steel can crack concrete.QUOTE]

I used steel in the foundation of my garage because that is what the B/O said to do. I did not coat, wrap, paint or tar the steel. Do I need to worry about my foundation cracking? I saw steel laid into the freeway this summer, before the concrete was poured. I did not see any protection of the steel. Will the concrete crack?

 

[steveray]

FG....there are minimum cover requirements for concrete over rebar....ASCE 318 I think it is....depending on the application, 1.5 to 3"ish....

 

[jaycee]

There are various government projects going on in state of Hawaii due to spalling. Most of the deficiencies I've noticed was because the reinforcing steel had lack of concrete coverage. The state of Hawaii is paying big for the "minor" mistakes that the contractor/inspector missed. Keep up the good work gentlemen, and require that the minimum concrete coverage of reinforcing steel is met.

ALOHA

 

[JCraver]

FG....there are minimum cover requirements for concrete over rebar....ASCE 318 I think it is....depending on the application, 1.5 to 3"ish....

ACI 318, from the American Concrete Institute.

I'm rather strict about cover requirements here - too strict probably if you were to ask the contractors.... Rusty rebar will indeed bust the crap out of concrete though, so I'm gonna' continue to enforce it like I do.

 

[MASSDRIVER]

A little rust coating won't hurt "normal" flat work or slabs. It will sometimes get a light coat and stop there. The problem is around generally salty water conditions, like near a coast line. Then it burrows into the steel and causes flaking which expands the steel.

Brent

 

[ICE]

I don't know but I've been told that rust enhances the bond between steel and concrete. It's only if there is a loss of cross sectional area that is a cause to reject the steel.

 

[MASSDRIVER]

I don't know but I've been told that rust enhances the bond between steel and concrete. It's only if there is a loss of cross sectional area that is a cause to reject the steel.

Makes you wonder who would use bar so degraded that material has been lost to oxidation. That would be some real crap. I don't think I have ever seen something like that used, but I'm sure some have.

Brent.

 

[Msradell]

I saw steel laid into the freeway this summer, before the concrete was poured. I did not see any protection of the steel. Will the concrete crack?

I'm betting that the steel you saw blade for the expressway was green in color. If it was that's an epoxy coating and what's normally specified for highway construction.

 

[ICE]

Makes you wonder who would use bar so degraded that material has been lost to oxidation. That would be some real crap. I don't think I have ever seen something like that used, but I'm sure some have.Brent.

I've never seen it either but that's the code. I know a guy that used bed frames....hundreds of them....he owned a second hand furniture store/auction.

 

[MASSDRIVER]

I've never seen it either but that's the code. I know a guy that used bed frames....hundreds of them....he owned a second hand furniture store/auction.

Now see here!

I was sure I owned the "crap I've seen" title, when my dad and I did a block grant rehab house lift, and found out the entire sewer system was done in firehose, and garden hose for the supply.

Then you shell me like the Bismark drilling the Hood with bed frame rebar.

I got nothin'.

All is not lost though. I'm working in Hillbilly country up in Forestville so I still have a chance to redeem myself.

Brent.

 

[Phil]

The Concrete Reinforcing Steel Institute, CRSI, has a free tech note, Field Guide for Rust on Reinforcing Bars. See the link to CRSI 's free downloadable documents at http://www.crsi.org/index.cfm/landing/engineer

 

[JBI]

The folks who make it promote the heck out of it. The main 'issues' seem to be potential for damage to the coating that is not addressed at time of installation which can cause excessive localized corrosion and diminished bonding of the steel to the concrete. The comments I've seen relative to these concerns also recognize that concrete quality, proper re-bar placement, and excessive use of salts (I live in the northeast, so salt used for snow/ice on bridges/roads is an issue).

 

[mmmarvel]

Being a special inspector (for a testing lab - in my past life) I've done thousands of inspections of rebar for concrete. Roads, sidewalks, driveways, building foundations (one of the most interesting was the rebar mats, 4 of them, that were put on the bottom side of a jewelry store vault). Anyways, typically (90% of the time) a bit of rust on rebar is fine. I did a rehab on a parking garage recently where it was specified that the rebar be epoxy coated. Yes, proper coverage with concrete is the key element.

 

[Frank]

Being a special inspector (for a testing lab - in my past life) I've done thousands of inspections of rebar for concrete. Roads, sidewalks, driveways, building foundations (one of the most interesting was the rebar mats, 4 of them, that were put on the bottom side of a jewelry store vault). Anyways, typically (90% of the time) a bit of rust on rebar is fine. I did a rehab on a parking garage recently where it was specified that the rebar be epoxy coated. Yes, proper coverage with concrete is the key element.

Parking garages are always an issue with corrosion due to deicing salts carried in on the vehicles

 

[e hilton]

one of the most interesting was the rebar mats, 4 of them, that were put on the bottom side of a jewelry store vault).

I build a lot of banks, and the spec for the slab under the vault is 18" of concrete with minimum 4 layers of #6 bar 6" OC both ways. The concrete sub has to be careful about using the vibrator propery to get the concrete to fill all the gaps between the rebar.

 

[ICE]

Thanks for that. How about the walls.....and the ceiling.....what can you tell me about those?

 

[High Desert]

Nice try ICE. I've reviewed a number of banks and they don't like to give out the details of the bank vault, for obvious reasons.

 

[ICE]

Ya, I was surprised when he told us what the floor has in it. You've got to remember that Brent sees this.

If he's quick, he can become a sawhorse and edit his post. Or maybe fatboy and his pudgy little orange fingers can do it for him.

We have an ordinance regarding who can see plans....banks and ice cream parlors are off limits. The ice cream parlors I can understand but when was the last time anybody dug there way into a bank vault. Those enterprising sort of criminal are a thing of the past.

Nowadays the real crooks have the combination to the vault so it's just another box.

 

[MASSDRIVER]

3 Banks jobs in my time. (Construction ICE, CON-STRUC-TION).

Same grid as before, extended 3 feet out on all sides past the vault line, something like 2 feet deep. Steel and concrete layered wall and roof panels, like composite armor. All welded at the seams. The vault door and jambs were impressive.

I heard the good stuff is in the casinos though.

Thinking about pulling The Italian Job, but in Orange County. Gonna use a murdered-out 68 Camaro for the geteway.

You in?

Brent.

 

[mmmarvel]

I build a lot of banks, and the spec for the slab under the vault is 18" of concrete with minimum 4 layers of #6 bar 6" OC both ways. The concrete sub has to be careful about using the vibrator propery to get the concrete to fill all the gaps between the rebar.

The mats need to be off-set from each other so that someone trying to drill in from the bottom will encounter rebar, followed by rebar, followed by rebar. It was the only vault that I did, but I found it very interesting.

 

[mtlogcabin]

Thanks for that. How about the walls.....and the ceiling.....what can you tell me about those?

[h=2]The Future[/h]Bank vault technology changed rapidly in the 1980s and 1990s with the development of improved concrete material. Bank burglaries are also no longer the substantial problem they were in the late nineteenth century up through the 1930s, but vault makers continue to alter their products to counter new break-in methods.

At issue in the twenty-first century is a powerful tool called a "burning bar" or "thermic torch." Burning liquid oxygen ignited by a oxyacetylene torch, this bar burns much hotter than an acetylene torch, getting up to 6,602-8,006°F (3,650-4,430°C). The torch makes a series of small holes that can eventually be linked to form a gap. In the future, the vault manufacturing industry will likely come up with a means to combat the burning bar. Then perhaps criminals will find a more powerful tool, and the industry will change its products again. Vault manufacturers work closely with the banking industry and law enforcement in order to keep up with these advances in burglary.

Read more: http://www.madehow.com/Volume-7/Bank-Vault.html#ixzz38Odb00Yi

http://www.madehow.com/Volume-7/Bank-Vault.html

Here you go ICE. My advise is find an older bank

 

[ICE]

3 Banks jobs in my time. (Construction ICE, CON-STRUC-TION).Same grid as before, extended 3 feet out on all sides past the vault line, something like 2 feet deep. Steel and concrete layered wall and roof panels, like composite armor. All welded at the seams. The vault door and jambs were impressive.

I heard the good stuff is in the casinos though.

Thinking about pulling The Italian Job, but in Orange County. Gonna use a murdered-out 68 Camaro for the geteway.

You in?

Brent.

You need to rethink that. Go with a white Camry.

 

[e hilton]

There's nothing secret about bank vault construction. We use reasonable measures to keep the good people honest.

Modern vaults now have modular walls and ceiling, precast sections of very high strength concrete in sections about 2 ft x 8 ft or the height of the vault. Cast in place walls are a thing of the past. There are pieces of angle iron around the perimeter that is used to weld one section to the next. Typical walls are 9" thick, and the vendor is careful to include all necessary conduits when casting them, the word is that they are almost impossibble to drill when cured.

But the real security is cameras and alarms. We spend a ton on cameras, and the images are crystal clear, nothing like what you see on the news about the perps that stick up the local c-store, where you're lucky to tell if they are even looking at the camera.