Oligomictic alluvial aggregates: petro-mineralogical and geochemical evaluation of sandy gravel formations on the middle course of the Danube (Hungary)

This paper evaluates the applicability of Hungarian oligomictic alluvial gravel formations at two sections of the Danube river for construction use. The classification of these aggregates is more challenging than monomictic rock aggregates due to their heterogeneous nature. Multi-source clastic sediments cannot be characterized by single values of physical properties but only a distribution, and they are generally less predictable than monomictic materials. The possible applications in concrete manufacturing were evaluated by complex macro-microscopic petrographic, heavy mineral and nuclear analytical geochemical investigations. The two regions falling on the middle course of the Danube have similar sandy gravel formations, applicable as aggregates for conventional and unconventional concrete building purposes or road construction. Their utilization in open-air constructions might be problematic due to their probable alkali-silica reactivity.