Geotextiles and Geomembranes Instead of Concrete?

Couple problem I see with using aggregates is that if you use any type of equipment on it it's going to tear it up. There is also a chance of rutting, pushing and pulling, unlike when you using concrete. The surface also may not be level enough if you plan on stacking pallets, etc. Just my observations from using similar set-ups in equipment storage lots for maintence garages.

This is for bulk handling, but the owner is going to use front loaders to move the product. Yes, it is very likely that the floor tears with use of heavy equipment.

Once the surface starts to tear there is a good chance the fertilizer could enter your groundwater, or start accumulation along the membrane layer you might want to add drainage piping that leads to a separation chamber.

Yes, I have considered that. But I don´t know exactly how to do it.

The excavated surface needs to have a slight slope to a corner where you'll put your separator(sump). Lay down the lining place a layer of stone then lay perforated pipe down all leading to and connected to the separator. Cover the pipe with several more layers of aggregate. Then finish up the surface. There should be several generic design layout out on the web to look up. If you can't find any let me know I have a couple in PDF I'll send to you. You with have to watch your compaction, and there may be issues with the equipment damaging the pipes. The technique your looking at isn't really ment for heavy equipment.

Another concern I have is that Phosphate, a common part of fertilizer, does not react well with lime or limestone and moisture. It will release carbon dioxide and ammonia. Is there another type of aggregate that can be used?

Red gravel is also abundant in the area.

Could you please send me a link to the layouts? I don't know how to look for them.

Hi gussosa,

How are you?

Your suggestion of Geotextile+sand+limestone tiles.................... Am I right in thinking limestone tiles or is it just crushed limestone?

This does depend on for one, the thickness of the Geotextile?

1) In the first instance of tiles. What will prevent the tiles from 'rocking'?

2) In the instance of crushed limestone, how do you consolidate the floor without puncturing the Geotextile?

3) How would this last as long as a proper reinforced floor

4) Have you worked out any comparison costs between a conventional reinforced concrete floor to an earth/sand/limestone?

Hi babybear

I am thinking in crushed limestone. I hope the geotextile resists it.

The expected life for the warehouse is 10 years, 15 maximum.

I have my architect working on the costs of the alternatives.

Hi gussosa,

Thank you very much for the reply my friend.

It certain sound like a good idea. Depends on what is under the soil to help keep the overall structure solid? It also depends on what you class as "textile" or "Membrane" which can be twice the thickness of industrial plastic barrels!

I was on sites this afternoon where this very 'membrane' covers whole wherehouses.

The engineer of my supplier said he was going to calculate the adequate thickness for each membrane.

The geomembrane is pvc. I don't know the geotextile.

Hi gussosa,

Thanks for that info.

I think it stands a good chance of working when it is only taking the weight of vehicles. It is the wear from front loaders that could be the downfall.

As well as that you also need machinery like a heavy roller which you would not need with a concrete slab. All adds to the cost?

I will keep an eye on this post, but what I have heard so far from you and others I would think is more time consuming and the need to wait for machinery to arrive and find somewhere to put it on a tight site............?

Take care.

You might be able to get away with asphalt millings. You can get the millings usually pretty cheap from a contractor doing a resurfacing job. Just but it down and compact it with a 10-20 ton roller. You'll come out with a nice water proof surface that's easy to drive on and should last a long time.

I will check that, thanks.

I haven't tried this yet, but I have been studying Compressed Earth Block for construction applications, and, for your warehouse floor, this may offer a cost-effective solution without a membrane...

Wouldn't roller-compacted concrete be cheaper and quicker, with the same results?

Just asking, I am not a civil engineer.

Depending on your native soil on the site, it may be possible to mix and treat the upper 12" of the soil profile by adding 6% by weight of Portland Cement. If the soil is not suitable, i.e. granular with some aggregate, limestone aggregate could be added prior to the addition of the PC. This process is in wide-spread use for stabilizing pavement and building subgrade and it is much less costly than cast-in-place concrete.

The process would require a large soil stabilizer that looks like a cross between a pavment profiler and a rototiller. The aggregate, if it is required, would be spread in a controlled manner over the soil, then the PC would be spread in the same controlled manner, and then the mixing would occur with the addition of predetermined amounts of water to provide hydration of the PC and optimum moisture content for compaction. As the mixing progresses, it is followed immediately by a padfoot vibratory compactor, then by a motor grader and a smooth-drum vibratory compactor. If the area is graded flat to a close tolerance (+/- 1/2") prior to the spreading and mixing operation, then the final grading will be relatively easy to control.

If the moisture level is controlled during curing by means of misting or light spraying, and if the final surface is smooth and tight, you should have a suitable surface for your intended use. It will be as water resistant as concrete and far more water-resistant than recycled asphalt. As an added water-resistant effort, asphalt emulsion could be introduced during the mixing operation to enhance the matrix.

This process is used in the rehabilitation of public roadways that are suffering from weak pavement profiles and to provide economic use of the existing in-situ materials. For this purpose, some surface treatment is typically applied to resist weather and traffic erosion.

If there are no equipment resources like what I have described available in your area, don't allow yourself to be led into the use of crude mixing tools like discs and such, as your results will not be uniform nor satisfactory for your purposes.

Finally, this process does not require nor need the use of geotextiles, but it should involve the input and recommendations of a Geotechnical Engineer who is familiar with the process. Typically, soil samples are obtained, classified in a soils lab, followed by test mix analysis to determine the appropriate proportions of aggregate, PC, and water to provide the desired result.

This is a fertilizer plant, there are probably many regulatory issue to consider regarding the issue of an impermeable surface and O&M materials handling (the ability to clean up spillage). Typically, only HDPE is acceptable for impermeable surfaces where chemical exposures to waste are likely to occur. How to you maintain the liner and verify continued conformance (cracked concrete is easy).

The geomembranes and geotextiles are the standard approved solution for building waste treatment areas. And then I saw a report on the use of geotextile+geomembrane+crushed limestone+dirt for the floor of an industrial cattle barn, for milking.

That's how I came with the idea.

An "ounce" of (prevention), in this case, may be worth several "pounds" of (cure)...

But first, the characteristics of the intended storage facility are not provided.

Is it to be a totally enclosed warehouse?

Or within an open-sided structure?

Or an totally open area on the ground?

Of about how much in length and in width?

Also, fertilizer could be under rather stringent environmental controls in the near future, if not at the present, and might well be taken into consideration before "breaking ground" on such a project, rather than afterwards...

How do you expect the fertilizer to be handled in the placement, and in the removal, or relocation, of it? With front loaders, power shovels, and/or hand shovels? Use of mechanical equipment would tend to tear up the surface upon which the fertilizer is to be placed after only a few (handlings), so a membrane on the surface of any such pad would probably not last long at all...

Depending on the chemistry of the fertilizer, there will generateration of gases, and some fluids as well, and I'm sure that's no surprise at all. However, how are those gases and fluids to be handled? You might want to consider including a system of perforated underdrains to carry any fluids to nearby sumps for proper removal and disposal...

Also, if the fertilizer is to remain undisturbed in place for long periods of time, you might also consider a system of over-drains to lie on top of the fertilizer, and adding an impervious membrane covering all of undisturbed portion(s) the fertilizer, with an an appropriate number of vertical vent risers to act as chimneys to disperse the gases to the air, or to manifold to collection tanks for (subsequent means of disposal, or re-use, through legally allowable environmentally appropriate means of that location...)

Maybe, its better that you're not in the U.S. and not subject to what ever obstruction the envirocrats can think up, yet...

In any case, the bitterness of poor quality is remembered by the client long after the gratification of rushed-production is forgotten by the vender...

And even with the envirocrats the fertilizer plants in the US still have plumes of contaminated ground water underneath them. Surpirsing how the word agriculture can buy a company pass from environmental complaince sometimes.

This will be a ClearSpan fabric structure, with three doors on it. The fertilizer will be granular, handled with a front loaders. It will arrive in dumper trucks.

The facility is close to a river and there is a cellulose warehouse nearby and the area regulations demand to avoid any possible contamination.

My basic idea is using a floor in layers: