Corpses and Concrete

[Coppernerves]

So I've heard that when volcanic ash gets rained on, it forms a kind of mud slide called a lahar, which after stopping, dries as hard as concrete in seconds.

Does that work with other kinds of ash? If you cremated enough corpses could you make the ash into a kind of mortar, mud, or concrete to build an extremely ominous palace out of?

Or is it just volcanic ash which does it?
And why does it do that?

 

[Quaxar]

Well, I'm no geologist, vulcaologist or any other related-ogist (geneology joke!) but I'm guessing that since <url=http://volcanoes.usgs.gov/ash/properties.html>volcanic ash is mostly "small jagged pieces of rocks, minerals, and volcanic glass the size of sand and silt" while <url=http://en.wikipedia.org/wiki/Cremation#Ash_weight_and_composition>human ash is "dry calcium phosphates with some minor minerals, such as salts of sodium and potassium" those two don't have much in common when it comes to building.
So my tip is no.

Although it might be possible to use the calcium phosphate as a substitute for calcium carbonite in <url=http://en.wikipedia.org/wiki/Cement#Types_of_modern_cement>Portland cement, depending on the chemical properties needed but I can't really be bothere to look any more into that matter myself, I'm hoping for a specialist.

As for the why, here's two nice links:
http://www.romanconcrete.com/docs/spillway/spillway.htm
http://www.scribd.com/doc/931856/Laboratory-Test-of-Volcanic-Ash-as-Concrete

I'd love to help more but seeing as my uni exams are up in a week I'd much rather study my own stuff instead of geology and concrete's structural and chemical properties.