Some articles on duagg:

Ducrete - Description
... In order to overcome these issues, DUAGG was developed ... DUAGG (depleted uranium aggregate) is the term applied to the stabilized DUO2 ceramic ... DUAGG has a density up to 8.8 g/cm3 and replaces the conventional aggregate in concrete, producing concrete with a density of 5.6 to 6.4 g/cm3, compared to 2.3 g/cm3 ...