# Red spots on new concrete???



## JGCConcrete (Feb 19, 2013)

Here's an updated picture, this is how it looks when it's wet.


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## jomama (Oct 25, 2008)

JGCConcrete said:


> View attachment 87935
> 
> 
> Here's an updated picture, this is how it looks when it's wet.


Superseal asked if it was covered, didn't see a response yet, but I think that's an important question to answer.

It's not from the oxidation of any rebar or mesh.

It very well could be dirt that got blown across the slab on a windy day?

I've had a similar problem many years ago (although not nearly as bad as these wet pics show) and after the RM supplier had 8-9 different "experts" looked at it, I came to the conclusion that the solvent-based sealer pail had rust in it. By the next fall, it had disappeared. Actually, I had the problem again last spring when my employees didn't notice that the water-based sealer that sat in the shop in the metal 55 gal drum over winter had turned orange from oxidation, at least until they were done sealing the driveway.............


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## JGCConcrete (Feb 19, 2013)

jomama said:


> Superseal asked if it was covered, didn't see a response yet, but I think that's an important question to answer.
> 
> It's not from the oxidation of any rebar or mesh.
> 
> ...


It wasn't covered with anything nor sealed, or even cured with anything, only water.


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## Ninjaframer (May 28, 2011)

I wonder when the last time the truck that poured that had dye in it.


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## jomama (Oct 25, 2008)

Any chance the wind blew that loose dirt across it???


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## superseal (Feb 4, 2009)

Something's going on there big time,...I'm around concrete everyday - buddy owns the local plant, another buddy is the batch master and as much concrete as I do, I never seen anything like that with exception to a contaminated mix. 

When colors are used at our plant - the trucks are always washed out and then usually sent to footing or fill jobs for the next batch just to ensure there clean. 

Maybe the bulk hauler pumped fly ash into the wrong silo at the plant that day because something is definitely funked up.

I'll run this by the batch master tomorrow see if he can come up with anything.


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## parkers5150 (Dec 5, 2008)

its definately not rust... my opinion is that somehow the mud you got was contaminated from the get go. Look at the color of the slab where the forms were pulled... that will tell you that it wasnt something spilled on top and more importantly will show the conc. rep that they need to send you some new mud:thumbsup:


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## AmeliaP (Apr 22, 2007)

Call the concrete company and ask them to come take a look. Maybe it depends on the company but we did that once and they nailed the problem (it was with the mix) right away.


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## superseal (Feb 4, 2009)

Well, I talked to the batch master this morning and showed the pics around the shop - bunch of us hanging around because of the rain...

Seems like the general consensus was in fact... RUST - I know, and I said earlier no way no how. 

Not from the reinforcing mat or bar like several have been thinkin', but from potentially a rusted drum or high iron content aggregate. 

Batch master informed me if the truck has been sitting idle for awhile, they'll fill her up with water and let her spin. When the water is ejected, it's like a river of red he said. 

In addition, we have the luxury of having the Lehigh Valley close by which produces high quality limestone based aggregates - others may not be so lucky and end up with high iron content materials.

Not really sure if this is what is going on with that slab so I would probably call the company and complain about the product. You could also core it and have it analysed and see what that shows. 

Let us know what you come up with - I'm curious to follow this through.


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## Tscarborough (Feb 25, 2006)

My guess is that there was a big clump of clay in the coarse aggregate.


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## fjn (Aug 17, 2011)

Ninjaframer said:


> I wonder when the last time the truck that poured that had dye in it.






Around here,you can stand on your head and spit nickles,no concrete company will let you get within 100yds. of one of their trucks with dye.


THIS, is exactly the reason.


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## wizzer (Aug 21, 2008)

Does your customer have well water ? Once misted with a line that had been 
turned off for the winter . I was the first one to use it that spring . Iron in the 
water caused staining . My two cents .


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## NYCB (Sep 20, 2010)

fjn said:


> Around here,you can stand on your head and spit nickles,no concrete company will let you get within 100yds. of one of their trucks with dye.
> 
> 
> THIS, is exactly the reason.


Interesting.

Most companies here offer colors, and if have your own they don't care if you toss them in.

I did get hit with a $50 charge last year from a company I hadn't used before. Said it was extra fuel to clean the truck out so there was a color surcharge.


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