Mechanically Milled Boron-Added Cement: Structural Integrity and (η, γ) Radiation Shielding Performance

Traditional shielding materials like lead and heavy metal composites are effective but have environmental and mechanical drawbacks, driving research toward alternatives that ensure both structural integrity and radiation attenuation. This study investigates the incorporation of boron into cement to enhance its microstructural, mechanical, and radiation-shielding properties. The microsized composites were produced by mixing boron at varying concentrations of 2%, 3%, and 4% wt using a mechanical milling process. The microstructure of the boron-added cement composites was characterized using X-ray diffraction and scanning electron microscopy, with chemical composition analysis performed via energy-dispersive X-ray spectroscopy. The modified cement powders were subsequently cast into 60 mm × 60 mm × 60 mm cubic concrete specimens and subjected to various performance tests. Key parameters evaluated include sound permeability, compressive strength, water absorption rates, radiation shielding effectiveness, and electrical surface conductivity. The calculation of the thermal and fast neutron total macroscopic cross-sections was performed by using the MCNP6.2 simulation code and gamma-ray LAC and HVL parameters by using the Phy-X program. It was revealed that boron addition significantly enhanced the thermal neutron shielding properties of cement, with macroscopic cross-sections increasing up to eight times compared to boron-free samples. The mechanically alloyed process improved density, leading to better fast neutron attenuation. However, while boron-doped samples excelled in thermal neutron shielding, no significant improvement was observed in gamma-ray attenuation, where the lowest HVL values were recorded for the MA-treated sample (C2).