Influence of ulexite content on radiation shielding properties of siderite aggregated concretes

This study evaluates the gamma radiation shielding performance of concretes incorporating varying ratios of siderite and ulexite, with a focus on quantifying the impact of ulexite content on shielding efficiency. Since personnel working in environments such as X-ray facilities and surgical suites are routinely exposed to ionizing radiation, the construction of radiation-shielded spaces is both a legal requirement and a practical necessity. To explore their potential for use in such applications, six concrete mixtures with different siderite-ulexite proportions were prepared in accordance with TSE EN 206+A2 standards. The linear attenuation coefficients (μ) of the samples were experimentally measured using a NaI(Tl)-based gamma spectroscopy system at photon energies of 662, 1173, and 1332 keV (emitted by ¹³⁷Cs and ⁶⁰Co sources), and theoretically calculated over the 15 keV to 15 MeV energy range using the Phy-X/PSD code. A strong agreement was observed between the experimental and theoretical μ values. The experimentally determined μ values were subsequently used to calculate the mass attenuation coefficients (MAC). The results demonstrate a clear correlation between the μ values and the siderite/ulexite ratio: increasing siderite content improves shielding effectiveness, while increasing ulexite content reduces it. Overall, concretes containing siderite aggregates exhibit superior gamma-ray shielding performance. Additionally, the Phy-X/PSD code has proven to be an effective tool for predicting the radiation shielding parameters of concrete materials.