Radiation hardening of constructional cement–magnetite–serpentinite composite under gamma irradiation at increased dose

Abstract

It is shown that a constructional radiation-shielding composite material with high resistance to radiation-thermal loads can be obtained. The material was produced using a Portland cement mix, boron-containing chrysotile, magnetite filler, plasticizing additives, and metal fraction by the vibro-packing method. The content of chemically bound water was at least 1.5 wt %. Exposure to high doses of gamma radiation led to formation of monocalcium ferrite CaFe₂O₄ with high physical and X-ray density in the cement–magnetite–serpentinite composite. Its formation resulted in radiation hardening and increased the mechanical strength of the composite up to the dose of 10 MGy. When a protective composite was exposed to γ radiation with the absorbed dose of 20 MGy, the mechanical strength of the composite was reduced by only 4–5% compared to that of the unirradiated sample.