Compost Facility Pavement 1

[lovethecold]

I have been tasked with designing a pavement for a composting facility. The purpose will be to place bituminous pavement over an area to place compost to decompose in the open air.

My question is, will the decomposing of the compost damage the asphalt? I understand that ammonia is produced during decomposition. How resistant is asphalt pavement to ammonia. Or will the damage (if any) be largely relegated to the heat and humid environment created during decomposition.

Is there something else that I may have missed?

Thanks for any help.

- EIT Geotechnical Engineer. I am here hoping to help, and learn a little along the way.

 

[Unotec]

I'd much rather do compacted clay with drainage control or, depending on the size, concrete.
You might want to consider using a liner below your floor. All depends what leachates are expected.
What are you composting? how are you planning to turn the windrows? Or is it going to be piles? How are you going to work them?

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[MiketheEngineer]

If I am correct - there will be quite a bit of heat generated. Not enough to start a fire but still plenty warm.

 

[lovethecold]

The area is outside. I am unsure of the actual equipment that would be used, but the compost is windrowed. I don't know what sort of leachates should be expected. It is largely for decomposition of grass clippings and leaves, some wood chips are added for aeration. I checked, and the city doesn't want to pay for concrete.

Thanks.



- EIT Geotechnical Engineer. I am here hoping to help, and learn a little along the way.

 

[AMN4]

What little I know comes from a project where yard waste was composted with sewage sludge using the aerated static pile method. An asphalt base was constructed to contain the leachate, which was piped to a sanitary sewer. Usually, the compost stayed between 50 and 60 degrees (C). A blower would switch on if the temperature rose too high. If the pavement got beat up, I'd say it was due to the front end loader used in the operation.

Unless the city plans on composting the yard waste with sewage sludge or other waste material, or drinking water wells are in close proximity, I would question the need for pavement beneath the windrow. Usually, the concern with ammonia is the disagreeable odor, especially if the facility is located in a residential area.

 

[bimr]

The maximum temperature is approximately 65 Deg C and the temperature should not harm the asphalt.

From the Washington Design standard:


(iv) The compost pad shall be constructed of materials such as concrete (with sealed joints), asphaltic concrete, or soil cement to prevent subsurface soil and ground water contamination;

http://apps.leg.wa.gov/WAC/default.aspx?cite=173-350-220

If you build this compost facility correctly, you are going to have to build a stormwater runoff and collection system for it.

Compost piles may be placed under a roof or out-of-doors. Placing the piles out-of doors, however, exposes them to precipitation, which can result in runoff or
leachate. Piles with an initial moisture content within the optimum range have a reduced potential for producing leachate. The addition of moisture from precipitation,
however, increases this potential. Any leachate or runoff created must be collected and treated or added to a batch of incoming feedstock to increase its moisture content. To avoid problems with leachate or runoff, piles can be placed
under a roof, but doing so adds to the initial costs of the operation.