Material selection and mix design of radiation shielding concrete

Based on the compiled literature and the availability of materials that could be used, concrete was selected as the best shielding material. Further work was carried out to develop a specific mixture that would shield the radioactive energies. The important special concrete ingredients that were considered in the mix design were high density aggregates and boron-containing aggregates. Various high density concrete mixtures of w/c (water/cementitious ratio) = 0.42, 0.45, 0.5 and 0.6, were prepared and adjusted appropriately in order to obtain the desired mix characteristics. The final (high density shielding concrete) mix produced was workable and cohesive with average 28-day compressive cube strength of 30 MPa, w/c = 0.51 and density of 4231 kg/m(3). The concrete had high slump with a height and spread of 230 mm and 510 mm respectively. It was composed of CEM 52.5 N, silica fume, water, hematite sand, hematite stones, steel shots, colemanite and chemical admixtures.