Volcanic ash may have preserved Roman ruins (Good cement)

Discovery ^ | May 13, 2009 | Rossella Lorenzi

[decimon]

Is this what you were alludung to?

I don't know. And I don't want to know what "alludung" is. ;-)

'Pozzolith' could mean something or it could be just a convenient trade name.

[Drammach]

My Roman history professor told me years ago that one of the secrets to the durability of the roads the Romans built was the inclusion of volcanic ash in the mortar used to hold the stones in the fossa in place. Maybe it was still just a theory then (instead of a proven fact), though.

Your professor was right, and it's been known for quite some time.
Volcanic ash and stone was used in the concrete used to make roman fish pens.
The ash's addition makes a "hydraulic" cement, capable of setting under water.
There was also a roman governor in ancient Israel that used the same hydraulic concrete to build massive docks and seawalls in a city called (IIRC) "Ceasaeria".. (sp?)

Romans also added wheat flour to their mortars and cements.
The gluten creates a glue that helped the mortar / cement to bond more firmly to the stones used to build walls.

http://en.wikipedia.org/wiki/Caesarea_Maritima

Scroll down to the chapter on the harbor.

[Hegemony Cricket]

Is that perhaps like “alludung are belong to us”?

[decimon]

Is that perhaps like “alludung are belong to us”?

Alludung is raining on us.