Assessment of Radiation Shielding Property of Heavyweight Concrete Incorporating Hematite Iron Ore

Construction Material and Technology

Abstract

The aim of this research was to produce and assess the property of heavyweight concrete which could be used to shield photon radiation. The shielding capacity is achieved by incorporating a denser aggregate into the concrete mixture. The concrete is prepared by partially substituting basalt aggregate with hematite ore. Five concrete mixtures with varying content of hematite aggregate per total volume of coarse aggregate (0%, 25%, 50%, 75% and 100%) are produced in the laboratory. Three concrete slabs with a dimension of 200*200 mm sides and 100 mm thickness are prepared as a representative for each concrete mixture. The photon radiation shielding property of the concrete samples is evaluated using two separate experiments. In the first experiment Cesium-137 is used as a gamma radiation source and radiation survey meter was used to measure the intensity of radiation passing through the shield. In the second experiment Cobalt-60 is used as a radiation source and a combination of ionization chamber and an electrometer is used to measure the dose. The result of the experiments showed that radiation shielding property of the concrete increase with an increase in hematite content. For a Cesium-137 source with a radiation intensity of 0.64 µSv/hr. at 1 m in straight line, the linear attenuation coefficient of the samples increased from 0.023 for normal concrete with no hematite to 0.127 for concrete with 100% hematite coarse aggregate. For Cobalt-60 with energy 1.25 MeV, the linear attenuation coefficient of the samples increased from 0.135 for normal concrete with no hematite to 0.196 for a concrete with 100% hematite coarse aggregate. Generally, heavyweight concrete which is made of hematite is found to be good for gamma radiation shielding purpose.