The Effect of Barite Content on Anti Radiation Properties of Geopolymer Fly Ash Concrete Incorporated Natural Rock Ores of Hematite

. In this study, the effect of barite mineral (BaSO4) loading rates and its dispersive manner within two types of heavy constructive concrete matrix on anti radiation attenuation coefficients was investigated. To attain this goal geopolymer concrete based on fly ash and Ordinary Portland cement concrete of different barite additions were fabricated and examined. Similar proportions of natural mineral rocks (Hematite) rich in iron acquired from the north part of Iraq (Al-Sulaimanya site) as aggregates was added to the two concrete mixtures to enhance their density. Then fabricated cured and dried samples were assessed for their anti radiation attenuation properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised 137Cs and 60Co radioactive elements with photon energies of 0.662 MeV for 137Cs and average energy level about 1.25 MeV for the 60Co. Likewise, the linear attenuation coefficient (cm-1), mean free path mfp (cm), half value layer HVL (cm), Compressive Strength (Mpa), Density (kg/m3), Water Absorption ( %) for the tested samples were obtained. The maximum linear attenuation coefficients () were attained for ordinary concrete incorporates barite of 75 wt. %. They were of 0.459 4.7 10-2 for 137Cs and 0.371 3.3 102 for 60Co. For geopolymer they were of 0.396 4.9 102 for 137Cs and 0.316 4.7 102 for 60Co. Substantial improvement in attenuation performance by 15 %20 % was achieved for concrete samples incorporate barite at different (15 %75 %) loading rates. The microstructure, concrete density, homogeneity and particulate dispersion were examined using different metallographic, microscopic and measurement facilities. It was found that as the loading barite level is increased within the concrete mix the linear attenuation coefficient is improved for both the geopolymer and ordinary samples.