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

Abstract

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.

Hungarian Fine-to-Coarse Aggregate, a Possible Constituent of Near-Vessel Structural Concrete of Nuclear Power Plants

“…The greatest depletion is observed in the NWHR in the Babót samples, where all major-and trace-element concentrations are much lower than in other mines. It is conspicuous that the Babót samples are much depleted in Ca and enriched in Mg compared to other samples of the NWHR, reflecting a higher amount of dolomite in the carbonatic components of the sedimentary beds [12]. While in the SWHR the Ca and Mg concentrations are more variable, the Mg concentration is still higher, reflecting the presence of dolomite.…”

“…In the Mid-Danubian region (MDR in Figure 1, e.g., Délegyháza, Bugyi), Pleistocene-Holocene terraces of the Danube are covered with fine-medium-coarse-grained sand and fine-grained gravels with well-rounded and medium spheric shapes [21][22][23]. The geology of the Danube's catchment area is variable, due to the bulk transported by the Danube from the western mountainous regions and by the tributaries inside the basin representing local lithology [12]. The erosional area is dominated by metamorphics of the Bohemian Massif, the Alps, and the NW Carpathians.…”

“…The concrete structures of the Hungarian nuclear reactors and their shielding will be made preferably using domestic raw materials. For this reason, we screened the compositions of sand and gravel materials from different sources in Hungary using analytical and petrographic [12] methods, and thereby we contribute to the development of a radiationresistant, durable, and low-activation concrete.…”

On the Geochemistry of the Danube River Sediments (Serbian Sector)

“…Regarding sediments, excepting the Danube River at the entrance in Serbia, the another three important sources of depositional material transported by the Tisa, and Velika Morava, the main Danube tributaries along Serbian Sector [2]. Given su versity of tributaries, of which catching basins cover a significant area with various morphologic characteristics, it is expected sediments to show a complex mineralogy Indeed, according to [3], the main constituents of the lithic fraction of sedimen quartzites, calcite, and carbonatizated microcrystalline quartz, as well as heavy min such as garnets, associated with opaque minerals, green and brown amphiboles, ort The Pannonian unit, which flows the Pannonian Basin, presents typical characteristics of a low-gradient fluvial river, such as a sandy riverbed, bifurcating courses with numerous meanders, sand islands, and sandbars. Sedimentary material shows a well-evidenced stratification, which should reflect also the Pannonian Basin geochemistry and mineralogy, the main source of depositional material.…”

“…Indeed, according to [3], the main constituents of the lithic fraction of sediments are quartzites, calcite, and carbonatizated microcrystalline quartz, as well as heavy minerals such as garnets, associated with opaque minerals, green and brown amphiboles, orthopyroxenes, etc.…”