These elements are not typical for pozzolan.

ash (pozzolan) and water...SIMPLE AS THAT.

George Wendell Hollon has written:

'A Correlation of published data on lime-pozzolan-aggregate mixtures for highway base course construction' -- subject(s): Lime, Pavements, Pozzuolanas

They attached the tesserae, or small tiles to the floors with mortar just as some mosiacs are still attached today.

From Musivarius:

The Romans used a mix called Pozzolan, volcanic rock crushed and mixed with lime.