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A unique brick series based on Vietnamese clay was manufactured at 114.22 MPa pressure rate for γ-ray attenuation purposes, consisting of (x) metallic waste & (90%-x) red clay mineral & 10% (hardener mixed with epoxy resin), where (x) is equal to the values 0%, 20%, 40%, 50%, and 70%. The impacts of industrial metal waste ratio in the structure and radiation protective characteristics were evaluated experimentally. The increase in metallic waste doping concentrations from 0% to 70% was associated with an increase in the manufactured brick's density (ρ) from 2.103 to 2.256 g/cm3 while the fabricated samples' porosity (Φ) decreased from 11.7 to 1.0%, respectively. Together with a rise in fabricated brick's density and a decrease in their porosities, the manufactured bricks' γ-ray attenuation capacities improved. The measured linear attenuation coefficient (μ, cm−1) was improved by 30.8%, 22.1%, 21.6%, and 19.7%, at Eγ equal to the values respectively 0.662, 1.173, 1.252, and 1.332 MeV, when the metallic waste concentration increased from 0% to 70%, respectively. The study demonstrates that manufactured bricks exhibit superior radiation shielding properties, with radiation protection efficiencies of 88.4%, 90.0%, 91.7%, 92.1%, and 92.4% for bricks with industrial metal waste contents of 0%, 20%, 40%, 50%, and 70%, respectively, at γ-ray energy (Eγ) of 1.332 MeV.

Once their life-span is finished, fluorescent lamps are usually processed in vacuum crushers because of their Hg content. This procedure generates glass waste and spent phosphor powders, among other residual materials. Due to their composition, glass waste and phosphor powders could be incorporated as secondary raw materials in the formulation of clay-based construction materials for non-structural applications. In this work, this incorporation was studied, focusing on the analysis of the formation of defects in the final product and its impact on the statistical variability of some physical and mechanical properties of the clay bodies, such as: density, linear shrinkage, water absorption, and compressive strength. It was found that a combination of factors, i.e. the presence of Pb and calcium carbonate in the waste glass, concurred to induce the formation of two kind of defects in the fired ceramics: internal blowholes and external glassy exudations. Despite the presence of these defects, the physical and mechanical properties of the test bricks produced were not statistically different from the standard formulation used as control. The implications of these findings on the possible application of spent fluorescent lamps wastes as an ingredient for clay-based bricks were also briefly addressed. [ABSTRACT FROM AUTHOR]