questionsis anyone concerned about the 'defective grout…

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Doesn't grout seal between joints and sections? It's not used to hold the bridge together, per se.

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@thunderthighs: Right but this particular grout is prone to rust and, if rust starts, it can spread. You do not want rust in your bridges.

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It just makes highway travel that much more interesting...one way to stay awake...hey kids, hold your breath till we go under the overpass, or over the bridge!

edit: I forgot to include mock terror while you say this!

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Rats. The tag-editors have struck again. One that was removed was 'Holy Clay, Grout Man'. Stolen from the truly creative collection of grout humor defacing a bathroom wall from college.

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Seeing as the DOT says it does not pose an immediate safety risk I'd say don't worry about it. You are far more likely to die from the semi w/ the rusty brakes behind you than the rusty grout on a bridge.

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I would be far more concerned with the structural integrity of some of the older spans that we all drive over every day.

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Should of checked Angie's list before they hired those contractors.

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@cengland0: The materials used to build bridges are specifically selected to not rust. Just because something next to them is rusting doesn't mean it's properties are somehow changed and it starts to rust. Even if some of the structure rusted, rust only happens on the surface, it can only travel inward if there is a defect like a crack or void. At that point I think most people will be more concerned about "cracks and voids" than "rust" on their bridges.

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Our infrastructure is pretty worn out in the U.S. I heard a figure that it would cost around 4 trillion to fix all of the infrastructure and that was a few years ago. That being said the chances of a bridge giving out while your driving on it are probably less than getting struck by lightning. The bridges are made to handle multiple times their actual intended weight. I guess just don't be in the wrong place at the wrong time.

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"grout contaminated with chloride making it prone to rust"???
For grout to be prone to rust it needs to have Iron in it... Some grouts have Iron in them as a means of sealing against moisture... Moisture causes the iron in the grout to rust and the grout expands better sealing the space or void that it surrounds... Look at the base of light poles the next time you are parked on the highway in commuter traffic, between the metal base plate of the pole and the concrete base it is bolted to will be a layer of grout or mortar about 1 to 2 inches thick... More often than not the layer of grout will look rusty, guess what it was made with....
I'm not sure what Chloride contamination will do to the cement used in the grout, more likely it causes it to age rapidly and fall apart exposing the metal underneath which then rusts... Is there a concrete or cement expert on Woot who can confirm this??? Sadly, Reporters rarely get the details right....

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@hobbitss: Thanks for the clarification. Reading through the thread I was wondering how a cement/sand mixture could rust. Now I know. :)

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The state of municipality is required to test materials used in highway/bridge projects. Hopefully this was done in a satisfactory manner so as to ensure there is no safety issue involved. In addition, all states have in place bridge inspectors whose job it is to ensure that there are no unsafe conditions. Again, hopefully they have done their job in a competent manner. There may be an issue of the subject grout not have its intended life span and the need to replace it sooner than later, but I don't think it is an immediate or even near catastrope waiting to happen. If you personally have any questions or concerns about highways or bridges over which you travel, you should definitely seek answers from the state or municipality in charge. That is not to say that everything is necessarily AOK, but at least it would generate a crew being sent to investigate.

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@hobbitss:

I don't think the grout itself is what they are worried about rusting. I believe the grout in question has been used to protect (coat) the steel cables supporting the bridge's structure. Since the grout is contaminated with excessive levels of chloride, it is likely to promote rust in the coated steel cables faster than expected.

Since these things are designed to last for quite a few years, this is not a safety issue because the cables will be inspected and replaced long before they rust to a dangerous extent. This is even more true since the inspectors, etc. are now aware of the corrosive grout.

The real issue is that these cables will (likely) need to be replaced sooner than expected, thus increasing the cost of maintaining this (relatively) new bridge.

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@baqui63: High School Chemistry was a very longgggggg time ago...
Is it Calcium Chloride we are talking about, also known as Road Salt????

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Yes, chemistry was a long time ago (and one of my favorite high school classes... only physics, electronics and video production were more fun).

Road or rock salt is generally sodium chloride, though fairly impure. The pelletized white ice melt sold to home owners for sidewalks tends to be calcium chloride. It is more expensive than rock salt but less damaging to concrete.

I doubt it much matters that much which chloride (sodium, calcium or whatever) as I believe chlorides are fairly damaging to steel regardless.

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Last week marked the 5th anniversary of the collapsed 35W bridge here in Minneapolis (where 13 died and hundreds were injured).

Anything that can cause bridges to fail is bad news.