Effect of heating on physical, mechanical, and nuclear radiation shielding properties of modified concrete mixes

Four concrete mixes, goethite-limonite concrete (G.L), barite-limonite concrete (B.L), steel slag -limonite concrete (S.L), and dolomite concrete (D.C) were prepared and designed to investigate the influence of heating (25, 100, 200, and 450 degrees C) on their performance as nuclear radiation shielding barriers. Slabs of different thicknesses from the investigated concrete mixes were exposed to a collimated beam of fast neutrons emitted from Cf-252 like fission spectrum, with activity of 1.05 mCi. Measurements of the attenuation properties of fast neutrons as well as total, primary and secondary, gamma rays were performed. Organic scintillation detector with stilbene crystal was used to detect fast neutrons and total gamma-rays intensities. Results show that G.L concrete has the highest value of total removal macroscopic cross-section, Sigma, for samples exposed to temperature up to 200 degrees C. However, for samples heated at 450 degrees C, G.L concrete has the poorest attenuation for fast neutrons. On the other hand, for total gamma rays, as temperature raising up to 450 degrees C, the B.L. concrete mix has the highest value of total linear attenuation coefficients (mu). Nevertheless; at 450 degrees C the S.L. concrete mix has almost the same value of as that of B.L.