Physico-mechanical and gamma-ray shielding characterization of monzogranite for sustainable shielding and construction applications

This investigation combines geological mapping, petrographic study, physico-mechanical evaluation, and a computational shielding assessment to describe the monzogranite and assess it for use as a natural radiation shield. Field observations demonstrate that monzogranite intrudes serpentinite, metavolcanics and granodiorite with sharp contacts, and is extensively sheared and jointed and exhibits alteration. Petrographic microscopy indicates two-mica granite with quartz, K-feldspar, plagioclase, muscovite and biotite as dominant minerals, along with zircon, monazite, allanite, titanite, and apatite as accessory high-Z phases. Major oxides geochemistry shows remarkable enrichment, especially in silica, alumina and total alkalis in the investigated monzogranite. Physico-mechanical analysis indicated density values of 2.58–2.70 g/cm3, as well as water absorption of 2.58–2.70%, compressive strength of 919–1104 kg/cm2, abrasion resistance of 16–18 mm, and a flexural strength of 15.3–21.2 MPa. A series of water absorption tests performed on certain samples shows a higher than normal porosity for microfractures, while nearly all of the samples have densities and other physical properties that are representative of monzogranite. Parameters for radiation attenuation were measured using Phy-X/PSD. The relationship between linear attenuation coefficients (LAC) and photon energy was found to follow a typical inverse relationship. LAC values ranged between 16.836 and 24.309 cm− 1 for low energies (0.015 MeV), decreasing to 0.055–0.059 cm− 1 at 15 MeV. Denser samples and samples which had a higher percentage of high-Z accessory minerals (MZ3, MZ4) showed increased attenuation. The variation in LAC follows the general trends associated with energy-dependent attenuation behavior. The performance of MZ3 and MZ4 was superior to that of other materials and provided better shielding against radiation; both materials contain high-Z accessory minerals and a higher density than other materials in this study. The attenuation capabilities of the monzogranite compared to conventional granite exceeded those of limestone and marble, indicating the monzogranite is a viable material to use for sustainable applications as a natural radiation-shielding materials and construction. In contrast to previous studies, which have mostly reported on bulk attenuation parameters, this study combines a thorough examination of the geology and mechanical properties of monzogranite to establish a correlation between mineralogy and density on the attenuation of gamma rays and to identify the best Pb-equivalent thicknesses for use in the practical application of monzogranite’s shielding capabilities. The monzogranite has moderate to high gamma-ray shielding properties and especially efficient protection at low energy applications, indicating it is a potential sustainable use as a radiation shield. The integrated geological, mechanical, and radiological dataset has enabled a more thorough evaluation of monzogranite as a potential natural shielding material.