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Paved sludge storage area

Paved sludge storage area

(OP)
Hello I need to build a paved storage area for WWTP sludge. I will have all organic soil removed, have base material and pavement. What is the recommended thickness, type of material under the pavement. note that there will be heavy loafers and dump truck going into this area, we have sometime about 10m high of sludge, the area is about 50m x 25m and it will be in a are experiencing temperature between -30C to +30C. Thanks. Eric

RE: Paved sludge storage area

Eric...you need to understand pavement design principles. You will not get a pavement design from this site for your application. That is not the purpose of the site.

You need to know that actual loadings expected, including both axle loads and wheel loads; you need to know the frequency that you expect those loads to be applied (how many times per day/week/month will the loadings occur?); you need to know how long you or your client expect the pavement to last (pavements have a finite useful life and a finite design life); you need to know the environmental parameters and their effect on the pavement (freeze-thaw, frost heave, hot weather, etc.); you need to know the location of the water table and how it will affect the pavement and you need to know the surface drainage characteristics and how those will affect the pavement. Further, you need to know what materials are available for the subgrade, base and surface courses and how those can be designed for thickness for your application.

Good luck.

RE: Paved sludge storage area

In addition to paving, won't you have to consider a seal of the area to prevent contamination of soil below? That falls into the category of sewage lagoon design, in part. Paving may not be accepted for that chore. Any wells in the area?

RE: Paved sludge storage area

(OP)
Thanks guys for the reply,

I know i won't get a design here... i will not design it my self... i am the 'owner' of the WWTP... i just wanted to know 'rule of tumb'... to have an idea how much it will cost me... Your comments will help to guide the guy that will design it for me. regards. Eric

RE: Paved sludge storage area

Whenever I'm asked about something like this, I just say "This isn't my job, but six inches of asphalt concrete over 4 inches of compacted aggregate base sounds about right." I think it's conservative. Other times I'll change to four inches of asphalt concrete over six inches of compacted base.
Then we hire a Geotechnical Engineer and he recommends the exact same thing.

RE: Paved sludge storage area

One factor sometimes goes unrecognized by engineers used to road jobs but for jobs like this. Slow turning truck movements have a major effect on the pavement, much more so than the number of repetitions and loads. So the design mix needs to take that into consideration, especially if hot weather is involved. Alternatively a rigid pavement of Portland cement concrete will avoid the problem. Also front end loaders handling the stuff can do damage. Are any tracked vehicles involved? About the worst for pavements if they turn much.

RE: Paved sludge storage area

(OP)
thanks guys,

the 10 wheelers will not do turns much but the loader will and no tracks there...

Eric

RE: Paved sludge storage area

without knowing subgrade conditions, impossible to design. but I would definitely not recommend asphalt concrete. use 5,000 psi concrete. assume you will have at least some thickness of aggregate base course (6 - 12 minimum) and I would not go less than 8 inches thick for the concrete and all layers could be thicker. In addition, I did not see any discussion of design life above. Is this pavement required to last 2 years or 50?

suggest you check out this site:
http://www.pavementinteractive.org/

RE: Paved sludge storage area

As usual oldestguy is correct, I agree with not using asphalt for this area reinforced concrete is the correct material in this case. I see this regularly when paving projects and have to explain to owners why the asphalt has failed or why it will fail. Dumpster pads is another problem area for asphalt. Concrete will cost more, but will last longer. You would likely start to see rutting in the asphalt after the first summer from the loader.

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