| Author | Message |
Stephen Perrera 
Posts: 823
Since: 5/27/2008
|  6/1/2008 8:15:29 PM 
quote: "The problem that those in-the-know are aware of is that no adhesive will stick to a slab that has that much fly-ash content (regardless of being broom-swept or not) and that applies to thin-set as well."
I'd like to view that file. If no one has made 40% how do they know it will not stick?
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David Kern
Posts: 518
Since: 2/20/2008
| 6/1/2008 8:49:27 PM
Lew made that statement to me based on information he was privy to. I have never known him to blow smoke.
All I can say is that there is going to be much $$$ spent in research by all parties involved including the American Coal Ash Association as well as the Concrete Industry & Flooring Industry which will include manufacturers.
If there wasn't a potential for flooring failure with the 40% CFA recommendation, there wouldn't be this much concern.
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/1/2008 9:06:20 PM
You sure work alot David. 
I had to cut off the last post quickly, there were some tacos with my name on them.Thanks for the acknowledgement.
I take it you found the website that quote came from. If not here it is.
flyash.com
Last Edited 6/1/2008
9:09:26 PM
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/1/2008 9:54:09 PM
typo
Last Edited 6/1/2008
9:56:56 PM
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/1/2008 9:56:12 PM
Looks like people have been researching tile thinsets and fly ash. I bet ya twenty bucks Lew has been talking to Howard Kanare about this.
Here's my take on it so far. If the addition of fly ash can inhibit MVE's and alkalinity problems it could well be an excellent trade off if adhesive manufactures can come up with formula's that will bond to it....like uh epoxy based adhesives.
click me
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/2/2008 9:38:49 AM
Stephen:
Nothing wrong with fly ash in appropriate amounts.
Example: Water is essential to life. Too much water can kill you. There was a Water Drinking Contest a year, or two, ago. The winner died of Water overdose.
A bit dramatic, but the point is the same with Fly Ash. It is the Percentage of fly ash the industry is concerned with. Too much is worse than none at all. Fly ash added to concrete results in less flex strength and the concrete becomes brittle... not good for buildings.
What we don't know about the old Roman Buildings is the amount of fly ash used and confirmed that indeed it was used.
Where did the Romans obtain the fly ash and was it fly ash as we know it or something else?
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/2/2008 10:11:04 AM
You should research that.
According to Lew Migliore's article I have read....MVE is the most common reason for flooring failures. Instead of trying to hold'm off at the pass perhaps they should delve into this anomoly where the use fly ash stops MVE and alkalinity like I read about in the article I posted
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/2/2008 7:39:38 PM
Good post Stephen. There is much to learn about concrete and fly ash.
I'm just concerned about cracking and movement with High Percentage Fly Ash.
Frankly;; I had never heard of bonding issues before this thread started.
I was in the concrete repair industry for about one year................. Testing and leveling concrete. It was fun, but I did not like it...
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/2/2008 8:34:20 PM
So....what about this slag cement.... concrete. Seems to have the same properties as fly ash and used in ratios of 20 to 80%?
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/2/2008 9:03:19 PM
Slag cement?
Don't know anything about it or if it is used in Concrete Sub-Floors.
What do you know about it Stephen?
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/3/2008 12:20:19 AM
Ray, you know what slag is. The remnants of iron ore processing. Its a glass like composite that is crushed and added not unlike fly ash. Has been used for many years in concrete with ratios like I listed above. It does the same thing as fly ash...like making it flow better, makes concrete less permeable and all that stuff.
Makes me wonder why its any different than fly ash or why there has not been any problems with this type concrete and floorcovering adhesives.
That reminds me. Didn't you write a book about concrete and flooring failures awhile back? Wasn't this in your book as well? Can you send me a copy or let us know where we can buy one?
Perhaps you could post it on floorreports.
Last Edited 6/3/2008
12:23:07 AM
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/3/2008 10:02:42 AM
Good site to read Stephen, Thank you.
I read the information. Good stuff.
Slag appears to be an upgrade to fly ash.
I would be willing to bet that slag, made from iron, is more likely Roman than fly ash.
I have no evidence, but Romans had glass and iron?
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Roger Gerber
Posts: 327
Since: 3/17/2008
| 6/3/2008 12:02:32 PM
Now that we are talking about slag, I found this article about slag and floors.
http://www.geoengineers.com/NewsDetail.aspx?Id=23
I have seen two floors where steel mill slag was used as fill underneath. Moisture raised one 4 inches in a couple of years. The other one just buckled.
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/3/2008 1:59:23 PM
Fill underneath the slab is far different than slag as an admix...
Or did I not read your post correctly?
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Stephen Perrera
Posts: 823
Since: 5/27/2008
| 6/3/2008 11:01:44 PM
Ray for the last time the Romans used volcanic ash which is called natural flyash.
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/4/2008 6:04:33 AM
ah. thank you.
So, not the same as the FlyAsh Association is bragging about.
All Fly Ash is not equal or is it?
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Jerry Thomas
Posts: 96
Since: 6/3/2008
| 6/4/2008 2:46:52 PM
Referring to what Roger said, I hired a paving contractor to pave my driveway which had a thick gravel base. I requested he widen it to accommodate more parking space. He used slag as a base and now that part widened section of the driveway is raised up several inches ..... buckles and cracks throughout.
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Ray Darrah
Posts: 1411
Since: 2/18/2008
| 6/4/2008 3:11:26 PM
the slab raised up like the maybe the slag swelled?
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Jerry Thomas
Posts: 96
Since: 6/3/2008
| 6/4/2008 4:02:28 PM
My driveway is paved with asphalt and the new parking area over the steel mill slag heaved and cracked. The part over the gravel base is in good shape.
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Roger Gerber
Posts: 327
Since: 3/17/2008
| 6/4/2008 7:29:31 PM
When groundwater hits the slag it swells up, I have seen it heave a 6 inch concrete slab 3 inches upward.
My concern would be if they use slag in a concrete mix what would the reaction be from the moisture. Have they done any testing (real world) not just theory. Would it affect the hardness or the strength?
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