Polymeric Sand

[AZRedhawk44]

So, I'm working a little bit here and there, fixing up my house's back yard.  Gutted the sprinkler system and practically rebuilt the whole stinking thing over the last month, I've put in grass in about 1/3 of the backyard (it's a big lot), and I'm getting ready to install a flower bed of some sort along the back wall of the house.

I decided I wanted some paving stones installed underneath the water spigot there.  Put a hose-reel right there, or something.  I want the whole flower bed to be 3 feet wide, and boxed in by 4x4 logs.  So, I got four 16x16 paving stones, which will fit in a 2x2 configured square, 32 inches deep in the space between the 4x4 log and the house wall, perfectly.

Reading up on installing paving stones.  You use "polymeric sand" as a fixing material.  Level the ground underneath, rub in some sand.  Then put your stones down, and put down more sand between the joints on the paving stones.  Then you get it wet.

So, when I bought my paving stones, I also bought a bucket of polymeric sand.

I smooth the area and open the bucket.

Huh.

Looks just like plain old sand to me, I think.  Oh, well.  I lay it down as instructed.  Put down my paving stones, put more sand in the cracks, sweep it in good, and hose it down.

It sets up a day later.

Looks VERY SUSPICIOUSLY like caliche.  Practically identical.  Looked identical, before, when it was dry and in the bucket, too.

I feel taken.

Why does Home Depot bother selling caliche-in-a-bucket in Arizona?  Or, is polymeric sand really different from caliche?  I plan on installing about a 50 foot walkway from my back patio to my workshop using paving stones and I'll want to do something to make them sturdy and stable... but I think I'd rather fill a 5 gallon bucket of sand in the desert than buy this sand at HD for $12 per 2 gallons.  I'll probably need 10-15 gallons of it to do the walkway.

[bedlamite]

http://www.groundtradesxchange.com/pavers/polymeric_sand.htm

The components of polymeric sand vary from manufacturer to manufacturer, but in general, the main ingredients are quartz and crystalline silica (usually 80-95% of the product by volume). Depending on whether the sand has an organic or man-made chemical binder, some include portland cement in their poly sand recipe, but all of them have a proprietary polymer/organic ingredient that is water-activated and acts as the binder between sand particles. It's this polymer that makes this sand so effective.

I'd be tempted to use normal sand and mix in 10% cement.

[Bogie]

easy answer...
 
Because it's a damn site easier to buy the sand, than to try to break enough of the "topsoil" up to use...

[Brad Johnson]

polymeric sand has a water-activated binding agent.  It will set up, but not as hard as concrete.  Looks like plain old sand until you get it wet.

Brad

[dogmush]

I use Play-Sand and portland and mix it myself.  The last time I did pavers it was about half the cost to do it that way.

But yeah, it's the water activated binder that makes it not just AZ sand in a bucket.  That and it's all sifted and the same color, so it looks pretty.