Penetrability of γ and Static Behavior of Newly Developed Concrete Using Different Passive Assay Techniques

摘要

This research work aims to investigate the penetrability of electromagnetic gamma rays and fast neutrons and the static performance of newly developed concrete. To achieve this target, seven concrete samples of three different coarse aggregates—dolomite, hematite, iron slag (with five different densities, i.e., 3.23, 3.34, 3.42, 3.10, and 3.03 g/cm3, respectively) with dolomite used as the control specimen—have been synthesized and investigated to determine their mechanical and radiation penetration properties. The mechanical performances were evaluated in terms of tensile and compressive strength, slump measurements, and water permeability. X-ray fluorescence was carried out to determine the chemical composition of the synthesized materials. The materials' mineralogical constituents were also determined by X-ray diffraction analysis. The radiation transmissioxn characteristics were also checked by using gamma-ray collimated beams of both ~(60)Co and ~(238)Pu/Be neutron source. A stilbene crystal organic scintillator coupled with a fast n/y pulse shape discriminating spectrometer as well as an NaI(Tl) scintillator gamma spectrometer were used to measure the radiation penetrated through the concrete samples. The fast neutron macroscopic cross section and total gamma-ray linear attenuation were derived for the developed mixes. The results obtained show that iron slag concrete of density 3.10 ton/m~3 has superior characteristics against the transmission of gamma rays and fast neutrons and distinguished resistance withstanding mechanical pressure and loads.