Differences in chemistry and mineral assemblages of Czech and Slovak serpentinite-type rock aggregates for mixed radiation shielding concrete

The chemistry and mineral assemblages of serpentinite-type rock aggregates used in radiation-shielding concrete vary, affecting the material's shielding effectiveness. These variations in aggregates result from different levels of serpentinization, leading to diverse compositions rich in serpentine, antigorite or lizardite minerals. These changes impact the overall radiation attenuation properties, differences in radiation-induced volume expansion, and concrete density. Understanding these distinctions is crucial when concrete mixes are tailored to specific shielding requirements in nuclear facilities. This ensures concrete-optimized radiation protection while maximising structural performance and durability. To identify such differences, a combination of Raman spectroscopy, large-area imaging and mapping using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) and powder X-ray diffraction (PXRD) was performed to compare Czech and Slovak serpentinite rocks which were used in the construction of local nuclear power plants, which are still in operation.