We've slowly (see: reluctantly) gotten into reinforcing pads with fly ash for ag producers in our area. It's been a learning process that has some how managed to turn out for us. Basically we get ~25 ton and disk it in to a 3000sqft area and dump a shitload of water in it, disk/blade/disk/water until it slowly hardens. All of our pads (4 so far) have turned out fantastic. The material is brought in with grain hoppers and I tell ya it's just a fantastic joyful process that leaves everyone in a great mood at the end of the day. We picked up another couple big ones about a week ago, (300x600) and I'm starting to think it may be worthwhile to improve our process. We aren't going to buy a conventional pulvamixer. That's simply not in the budget. What I would like to do is spend a little bit of nothing and really get a lot for nothing (ha). I started looking at 3point mounted pulvamixers, specifically these shown here https://www.iowafarmequipment.com/fae-tractor-pto-soil-stabilizers.html I think the only way making this move improves our process is if we get one that has the capability to inject water as it's mixing, which from my brief conversation with the salesman just isn't in the budget. I'm also afraid the dust from the mixing will be so bad without the water injection that it simply wouldn't be an improvement for us at all. Just was wondering if any highway guys here familiar with the **** had any feedback on the 3 point mounted machines or if we should just stick with what we're doing.
I would bet those 3pt. soil stabilizers are right up there with mulchers and $20K or more and then you need a BIG tractor to run it. Nothing cheap about it.
What would be wrong with using a rotovator with a water manifold attached to it and a water truck running alongside it on the dry side feeding it with a hose hanging off a boom attached to the truck? Mike
I watched a demo of one of the smaller FAE soil stabilizers a few years ago and with cement powder the dust wasn't bad, but the ground was wet when they put the cement down. Another thing to look into is putting the fly ash down as a slurry in front of the stabilizer.
Big AG tractor running the stabilizer, big saddle style sprayer tanks on tractor, hydraulicly driven pump for water and a spray bar of some sort spraying material being mixed..... just a thought
That was my thought too
When I worked for a large engineering company back in the 70's, we built some big "flyash test fills" to evaluate the use of flyash in dam building. It was found that "Lots" of water had to be added to the flyash to get proper compaction. We had a water tanker truck onsite for spraying water onto the ash after each lift was spread. We used a dozer pulling a big Rome disk, to mix the ash, dirt, and water. This worked great for lifts up to about 12" thick. It will take more passes with the disk, than with a stabilizer, but the mixing with the disk provided a very uniform material that compacted well. Something like this might work in your application.
Might want to look for one of these Semen Tillers. They are the original Pulvi-Mixers and will till 18" deep. I still see them for sale in the $2,000.00 range once or twice a year or so. Most of them have a 4-71 Detroit. The one I have came with three sets of new teeth. These were used to chew up asphalt in the old days and to mix asphalt and oil when they mixed the asphalt in place. For general rooting the owners manual says "with up to a three inch tree trunk we recommend you simply drive over them and grind them up. Equipped with two transmissions, one drive, one for the mixer.
I just wanted to thank everyone for the responses. Right? Welcome to the dirt business. I like this idea. We have a 631 water wagon that hopefully we could rig up a system of lines to get this to work. Lots of water is right. Right now as a rule of thumb we have about 8-10k gallons to cover 18,000 sqft or ~150 tons of FA. We have an aggressive disk but nobody wants to put a cat on the front of it and get it covered in FA. We've just been borrowing a big tractor and disk from a client. Everything we're doing is working ok, I'm just looking for a way to make it better. I've been keeping an eye out for one of those older units. Looks like a good holds its value considering they're 50 years old.
Boy O-I-H I sure was glad you posted that pic so I could see it was a "seaman" tiller...
Funny, I think I hate that auto spell check.
Reminds me of a joke I can't tell here but there's a submarine and a certain "orientation"
What are these pads used for jaclo? We live in a farming area with a big coal fired power station nearby, but I don't believe I've heard of any locals utilising fly ash for anything like this. Would be great to see some pics of the end result.
Yair . . . Crikey old-iron-habit pictures of that tiller bought back memories. I did a few shifts on a similar machine (I thought it had a 6-71 though). Very effective I thought. We were relaying an old bitumen road and they lay bags of cement out on the surface, the machine tilled them in and then the pass was watered and rilled up with the grader watered again I did a second pass and it was graded and compacted. Looking back it seems pretty simple compared to the huge "stabalizer" machines they use today
Fly ash is commonly used in the area here where I live. It was used on the NASCAR track in Joliet,Il. After the fly ash was incorporated into the clay subgrade it was compacted and then left to cure for seven days. It got so hard the graders could only shave a little at a time on each pass. It was quite entertaining to watch them grading the turns.
It's being used as a cost effective substitute for concrete for big piles of ag commodities. Silage or corn is usually what is intended to be piled. Threw together some pics for you http://imgur.com/a/EoNIO
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We have done quite a few of what you are talking about jaclo. I don't know all the reasoning behind the products we use as I'm the mechanic and not in the office but we have been using I think cement dust a lot lately on grain bunker pads. We used to have a Cat RM500 and now we have a Wirtgen WR200 and the company that hauls in the dust has spreader bars that spread out the dust and then we till it in and incorporate the water in the drum by pushing water truck and the person unhooking and hooking up the water trucks gets the worst end of the deal. We used to have a Howard Rotovator and pulled it with about a 220 hp tractor I think it was and in first gear on that tractor it was all the engine would do to power it and it was maybe a 7ft machine.
Glad it jogged some old memories Scrub. Pretty much everything in my collection of relics brings "old" memories to someone or another. Them old Tillers did a heap of work in there day.
You guys must get a few more pads every year than we do ha - I wish we could take a swing at some machinery like that. Commodities are going to have to get their **** together first. I really thought about that rotovator deal but to buy a good one you're looking at 10k which to me just isn't feasible. We're getting a good enough job done with what we're doing and I think we'll just stick with it. If it ain't broke etc..
Thanks for the pics jaclo. I'll have to ask someone closer to the power station what happens with the ash.
It gets mixed in cement as a bulking agent.
Pretty sure he is referring to his specific plant, he stated in another post that it really isn't used for pads where he lives. I suppose they have some kind of lagoon to store it?
As far as I know jaclo fly ash is trucked out dry in vacuum tankers by the cement companys. A 24-7 operation.
Can't you rent a mixer in you area? Man I would hate to run a disk mix in fly ash. I'm guessing there is not testing done to see if you have the FA mixed in properly? How many passes with the disk to mix it? Depending on the spec we usually make 3 with a mixer. That in turn does save we some water. I don't think you will find anything the will put water in it fast enough while it's mixing. It would also be incredible hard to gauge how much water to apply too. I doubt you can get FA in a slurry form it's not that common in our area where we stabilize everything. You may look into Portland instead for FA it would take a ton less water. However you have 4hrs from the time you start mixing it to finish and get it on grade or it turns to concrete.
I found this on the station's website, seems to be a waste of a useful byproduct. Fly ash management Fly ash is a by-product of combusting coal in the power station’s boiler. At Kogan Creek, more than 99.9 per cent of the fly ash is collected in giant vacuum cleaner-like filters. Captured waste ash from the electricity generation process is piped to the nearby Kogan Creek Mine site, where it is used to fill a specially designed ash cell. Once the ash cell is full, it will be capped with mine spoil, progressively rehabilitated with top soil and then revegetated.
You aren't wrong. It's a big suck. Last year we said we weren't going to do any more but they've turned out so good for our clients so we can't walk away from the business. No testing. We make multiple passes with the disk until it no longer raises itself off the ground with the disks and has visibly mixed with the subgrade as much as possible. We usually put on close to 10k gallons of water per 20k sqft or ~150 ton of FA. What we've learned is that there is no such thing as too much water. You can always come back from being too wet by running the disk over it and blading. Our client is a big ag producer and this is how they want to do it, so we roll with it. Complete pain in the ass though.
I thought there was a company in the Wichita area that was using Fly Ash slurry, but it's cement slurry. I asked a buddy from down that way about it and he sent my a link to this video.
Your right about the water. In fact you could just let sit until tomorrow and it would be bone dry. I've used FA to stabilize ponds that we where digging out or filling. Dump a truck of FA in water and it will start to boil from the heat of the chemical reaction. Using your clients tractors is a wise idea. Fly ash as hell on any kind of radiator long term.
hvy 1 ton we got slurry from Andale Ready mix on one of our jobs and that is nice they hauled it in and spread it and we tilled it in and compacted it. It comes from Martin Marietta but on Marietta site it says Andale is a dealer so don't know how that works. Its very nice that you don't have to have any dust to breathe in. On fly ash pretty much all I know is what I have read online and that is that fly ash has to be incorporated so long after it has had water applied to it because of its reaction so if it was mixed with water and then applied you would have a short amount of time to incorporate it, compact it, and grade it out. My understanding is hydrated lime is a product that is mixed with water and then spread and tilled in. We just did some parking lots on Thursday and Friday and used fly ash and it come from a Westar Energy coal fired energy plant somewhere up close to Kansas City and was hauled in pneumatic trailers and then they put a spreader bar on the back of their trailer and the semis spread it out for us and sometimes we have to spread it out just a bit with a loader or grader. Here is the link to what I read about fly ash and it talks a little about the different limes. https://www.fhwa.dot.gov/pavement/recycling/fach07.cfm
Hey still learn'n Was the parking lot then paved on top of the fly ash surface? Any ideas on tons per square foot you were putting on?
The dirt will get fine graded and get paved right on top of the dirt. The one parking lot was 26,358 sq. ft.and used 5 loads of around 26 tons each and the other was 35,226 sq ft and took 7 loads. Technically we go by what the geotechnical report says and it goes by the amount of dry dirt that is in the proctor is what I am being told and this was 14%. As I am the mechanic and just help out with the process I have to ask the office guy about all the technical stuff with this.
No that's what I was looking for these pads we are doing are basically taking double the amount of FA which is what I was wondering. Uploaded a pic of an in progress pad, this is just after running the smoothe drum.
Looking good. For some reason my email alerts haven't been working so that's why I didn't reply to your message earlier
If you are using fly ash for a stabilizer you may want to stock up as between cement plants and the damn EPA the availability is drying up. The company I retired from is no longer able by EPA rules to sell ash components from two of four dirt burners due to mercury contaminant. They adopted new scrubber systems where more mercury is collected in the ash so is no longer available for release and must by retained in impoundments forever.
How can you even store that stuff? I have never been to where they put it on the trucks but I always just assumed it was kept in a very large -heated- hopper of some kind. We don't do enough of these pads to justify investing in storage like that. As fun as they are not to do I'm not particularly sad about it either.
Plain fly ash is dry, REALLY dry and light like face powder only more intrusive into EVERYTHING!! A few trucking companies here haul it to concrete plants to use as a additive for lightweight concrete or to add to cement to make "Flowable Fill" for sites where they need the strength of concrete but not the aggregate and gain the ability to dig thru with a excavator or hoe.