How to test compaction on sites improved with Class C fly ash?
How to test compaction on sites improved with Class C fly ash?
(OP)
I am working on a site in the panhandle of Florida. The site soils are clayey sands with about 30 percent passing the No. 200 sieve. We have been getting large amounts of daily rain. The soils have become too saturated to compact. The project is on a strict time line and the weather outlook is not favorable. I am contemplating recommending using Class C Fly Ash to dry out the soils. THe site soils do not seem to be clayey enough to use Lime based upon the research I have done. The questions i have are:
How do you test compaction in the field? Standard nuclear guage testing?
Do you need to run a proctor sample mixed with fly ash?
How much fly ash would need to be added just to dry out the soils to get closer to the optimum moisture content?
Can you work with fly ash with daily afternoon rain storms? Or do you need an extended period of dry weather to use this material?
These materials (lime, fly ash, etc.) are not commonly used in Florida since most of the soils are clean sands to slightly silty sands. Any help would be greatly appreciated.
Thanks,
Guy
How do you test compaction in the field? Standard nuclear guage testing?
Do you need to run a proctor sample mixed with fly ash?
How much fly ash would need to be added just to dry out the soils to get closer to the optimum moisture content?
Can you work with fly ash with daily afternoon rain storms? Or do you need an extended period of dry weather to use this material?
These materials (lime, fly ash, etc.) are not commonly used in Florida since most of the soils are clean sands to slightly silty sands. Any help would be greatly appreciated.
Thanks,
Guy





RE: How to test compaction on sites improved with Class C fly ash?
f-d
¡papá gordo ain’t no madre flaca!
RE: How to test compaction on sites improved with Class C fly ash?
RE: How to test compaction on sites improved with Class C fly ash?
Density testing can be done with any of the typical methods; however, you should note that fly ash can actually hydrate in a manner similar to cement, so make sure the density testing is done right after the mixing and compaction process, not the next day....you might get failing results the next day because of chemical issues.
As for how much fly ash, you'll have to do a few trial batches with different percentages. Further, you can't work toward an "optimum moisture" because as the percentage of fly ash is changed, so will the optimum moisture.
Why are you using fly ash? I'm familar with the panhandle soils of Florida and you should be considering sand first over other materials. Sand mixtures are easier to predict and easier to control. Since you have not given the context of you issue, it is difficult to say which would be better, but generally sand is easier to deal with.
RE: How to test compaction on sites improved with Class C fly ash?
Importing slightly clayey soils (-200 about 10 to 15%) will be about $80k. After this weekend's rain, these too will be dificult to work with. I am trying to find a way to dry out the on-site soils with these constraints.
RE: How to test compaction on sites improved with Class C fly ash?
RE: How to test compaction on sites improved with Class C fly ash?
f-d
¡papá gordo ain’t no madre flaca!
RE: How to test compaction on sites improved with Class C fly ash?
This is extraordinary weather, even for Florida. Northeast Florida got pounded recently as well.
If I'm not mistaken, Pensacola has experienced upwards of a 100-year, 24-hour rainfall event once and a 25-year, 24-hour rainfall event once in the past week, along with heavy rains every other day.