Long-term behavior of normal weight concrete containing hybrid nanoparticles subjected to gamma radiation

Since a lot of medical facilities are made from normal weight concrete (NWC), it became an important task to improve the radiation shielding properties of such concrete in a confrontation to radiation with special emphasis on gamma radiation type. Therefore, an experimental program was conducted to investigate the effect of nanoparticles addition on gamma radiation shielding, physical properties, and mechanical properties of NWC. Nano silica (NS), nano hematite (NH), nano titania (NT), and their hybridization were added to NWC with four different percentages of 0.5, 0.75, 1.0, and 2.0% from the cement weight. A total of sixteen concrete mixes with nanoparticles in addition to a control mix were made. The long-term effects of gamma radiation on samples representing all concrete mixes were studied to find out the consequence of exposure to gamma rays over long periods (250 and 500 days) on their mechanical properties. The experimental results showed that the single addition of each of NS, NH, or NT particles and their combination up to 2.0% improved the physical properties, compressive strength, and attenuation coefficient of NWC. The results of the hybrid nano addition showed that the synergistic phenomenon occurred in some cases. Furthermore, the scanning electron microscopy technique (SEM) was used to prove the enhancement in the microstructure of NWC as a result of the addition of NS, NH, NT, and their combination.