Akademik Veri Yönetim Sistemi
Medziagotyra, cilt.16, sa.3, ss.249-256, 2010 (SCI-Expanded, Scopus)
Heavyweight concrete is widely used for radiation shielding of nuclear reactors and other structures that require radiation impermeability. Aggregates play here an important role - while hematite and other iron ores are commonly used for the purpose. However, little information on properties of hematite-containing concrete other than radiation shielding data has been reported. We have studied effects of different concentrations of hematite (10 to 50 volume % at 10 % intervals) on physical and mechanical properties of concrete. A unique water-to-cement ratio of 0.42 kg/m3 and 400 kg/m3 cement content was selected. Addition of hematite increases the unit weight (density) so that a smaller thickness of concrete is required to provide radiation shielding. After 30 freeze-thaw cycles the plain concrete looses 21.3 % of its compressive strength while the composite containing 10 % hematite looses only 7.8 % of the strength. Concrete and hematite composites have lower drying shrinkage than plain concrete, thus lowering stresses resulting from the shrinkage.