Fabrication and characterization of rubcrete-iron composite for mixed radiation shielding

Mixed radiation environments need unique shielding materials that can effectively attenuate photons and neutrons simultaneously. Most ordinary shielding materials can only shield one form of radiation effectively. In this work, a novel composite material was fabricated in our laboratories and characterized for photon and neutron shielding. Waste materials were used as partial substitutes for aggregates in concrete, which is a sustainable practice in the building industry at present. The main components of the composite material are iron filings, rubber, and concrete. Concrete samples were mixed with iron filings at varying percentages (0%, 10%, 20%, and 30%) and a fixed 5% crumb rubber content. The material’s photon and neutron shielding characteristics were evaluated through experimental and simulation methods. Gamma-ray attenuation measurements were experimentally carried out using a NaI(TI) spectrometer and a Cs-137 0.662 MeV energy source. In contrast, GEANT4, PHY-X/PSD, and NIST-XCOM codes were used to simulate photon and neutron cross-sections. The findings indicate that an increase in iron filings results in enhanced radiation attenuation, reflected by a higher linear attenuation coefficient (μ). The linear attenuation coefficient values range from (0.1590 ± 0.0004) to (0.2045 ± 0.0003) cm−1 for samples with no crumb rubber and from (0.1521 ± 0.0002) to (0.1920 ± 0.0004) cm−1 for samples with 5% crumb rubber. Half Value Layer (HVL) decreases with an increase in iron content and is slightly higher in samples with crumb rubber. The HVL results from simulations and measurements agree. This study optimizes the potential of concrete as a radiation-shielding material while promoting sustainable construction and environmental practices.