Accounting for Compaction and Moisture

Two of the most unique features of AggreGET are the segmented controls at the bottom of the app’s main screen.

When a do-it-yourselfer calls a quarry or a gravel pit for a material estimate, future compaction and a material’s current moisture content often go unaccounted for. Such oversights can significantly impact a project’s final quantities.

Compaction

The first control, labelled “Loose // +10% Compaction”, accounts for how the user plans to handle the material on their project site once they’ve unloaded and placed it.

While materials are usually dropped into the truck “loose” by a loader, once the hauler delivers that material to the project, plans often call for dumping, spreading, and compacting it to a certain degree.

Such compaction can be achieved by a number of methods:

  • drum roller
  • sheepsfoot
  • vibratory plate compactors
  • wheel-rolling (simply driving on it, and compacting it with your tires)
  • and natural settling via gravity and additional moisture

Because such methods can vary so greatly, I’ve set the default option to either 0% or 10%. I realize that compaction percentage can be a precision spec on some projects, and I hope to account for more precise degrees of compaction in future upgrades.

What’s the bottom line when accounting for compaction in AggreGET?

If you plan on driving on this material, you’re going to experience some degree of material loss due to compaction, settling, and erosion.

AggreGET lets you account for this quantity up front.

Material Moisture Content

Almost every material from a quarry or gravel pit will contain some degree of moisture within it–especially materials that are stored and stockpiled outdoors.

Drastic differences in moisture can vary from supplier-to-supplier. For instance, the material pumped and processed from a gravel pit will usually contain greater moisture than material stripped and processed from a mountain quarry.

Drastic differences in moisture can vary from material-to-material as well. Sand, gravel, clay, and dirt blends have sponge-like properties, and they absorb and preserve any moisture that is exposed to them.

Coarse rock and rip-rap, on the other hand, do not absorb moisture as well as finer materials. Why?

Let’s compare stockpiles of basic beach sand to stockpiles of river rock:

  • Large rock is more dense than sand, and water cannot permeate it as well.
  • A pile of large rock contains larger pockets of air than a pile of sand does, and this allows water to percolate downward and evaporate upward better in larger-grained materials.

In my app, sand’s additional moisture options are 0%, 10%, and 20%.

River rock’s additional moisture options are 0%, 2%, and 5%.

The segmented control at the bottom of the app has assigned each material a “Dry // Damp // Wet” rating.

In AggreGET, “Dry” refers to “normal” conditions. It does not imply that there is zero moisture in the material, only that moisture is 0% above normal.

A good way to tell whether your material is dry is to observe the face of the stockpile from where the material is being loaded. If the material isn’t caking together, and if you don’t see any wetness within the first 2-to-3 feet of the pile, then it’s considered “dry”.

“Damp” implies that the outdoor stockpile has been exposed to some moisture. That could mean moderate rain or snow, or it could mean that the supplier adds water to their products to keep the dust at bay.

“Damp” also means that the surface of the pile appears dry, but the surface underneath contains above-normal moisture. If the top 6-to-18-inches of the pile acts like a thick “scab”, but below it seems very wet, then AggreGET considers the pile “damp”.

“Wet” means that the pile is saturated. That could mean the supplier has just pumped said material from the waters of the gravel pit, or that torrential rains have soaked the pile recently. If the pile is wet on the surface, wet underneath, and water is spilling from the loader bucket or shovel, then AggreGET considers it “wet”.

Some things to consider when communicating with your supplier:

  • Did your supplier recently pump said material from a gravel pit (aka a pond)?
  • If so, is their loader operator loading said material from the dry end of the stockpile or the wet end?
  • Does your supplier store their materials indoors?
  • Does your supplier keep their stockpiles wet with a sprinkler or a water truck?
  • Has it rained recently? If so, in what quantities and how recent was the precipitation?

Final Thoughts

Just a reminder, you DO NOT need to account for moisture in bagged materials. Unless the bags have been tampered with AND stored outdoors, you will not need to use the moisture control for materials that you purchase in bags.

There are a few materials in AggreGET that will not offer you the option to use the moisture and/or compaction controls.

For instance, “Asphalt (Hot/Warm/Cold Mix)” and “Concrete (Bulk or Bagged)” do not give the user compaction or moisture options.

Why?

Because AggreGET assumes that “Asphalt (Hot/Warm/Cold Mix)” will be compacted by default, and that its processing prevents additional moisture.

“Concrete (Bulk or Bagged)” is not typically compacted and already boasts extremely high moisture by default.

There are other materials were the moisture and compaction controls are disabled by default for similar reasons. If you believe that there should be an exception for certain materials, please drop me a message or leave a comment, and I’ll consider including a change on the next upgrade.

Please leave any questions or comments below.

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