Producing Heavyweight High-Performance Concrete by Using Black Sand as Newly Shielding Construction Material

Radionuclides distribution and radiation hazards assessment of black sand separation plant's minerals: a case study

This study assessed the radioactivity levels and associated risks in the black sand-separated products obtained from the black sand separation plant in Delta, Egypt. A total of sixteen samples were taken from hot spots during and after the separation process. These include water samples and other samples that represent monazite, rutile, zircon, granite, ilmenite, and silica products. The hot spots included the area where the ore was stored. The activity concentrations of232 T h ,226 R a , and40 K were determined in these samples using a p-type HPGe detector. Based on gamma spectrometric analysis, samples of rutile, zircon, and monazite had the highest amounts of radioactivity because they contained the highest NORM's activity concentrations. In addition, it indicated that the radiological hazard indices of the collected samples were higher than the average world limits for sand texture. These findings suggest that the black sand separation process reveals potential risks to human health and the environment, and therefore, appropriate measures need to be taken to mitigate these risks, especially for the safety of the workers on-site. Reducing the risk associated with those sites should be controlled by implementing the recommendations declared for the series of International Basic Safety Standards of the International Atomic Energy Agency (GSR) Part 3, as affirmed in Document No. 103 of 2007 by the International Commission on Radiological Protection (ICRP) as will be presented in the paper body.

UPR/Titanium dioxide nanocomposite: Preparation, characterization and application in photon/neutron shielding

The aim of present investigation is to fabricate TiO₂ reinforced novel composites as an alternate nuclear radiation shields. Unsaturated polyester resin has been reinforced by the incorporation of different weight proportions of titanium dioxide (5, 10, 15 and 20 wt%) nanoparticles. Accordingly, mass and linear attenuation coefficients (μ_m & μ), half and tenth value layers (HVL & TVL), relaxation length (λ) and effective atomic numbers (Z_eff) have been computed. Gamma ray transmission set up has been employed for the determination of experimental μ_m values and consistency of experimental outcomes has been compared with the induced results from WinXCom program and Geant4 simulation code. Moreover, discrepancy of fast neutron removal cross section with the increasing TiO₂ content in the prepared composites has been studied. Additionally, structural properties in terms of XRD, SEM, RAMAN, FTIR and mechanical properties in terms of compressive strength have been analysed. The findings of this study revealed that the addition of TiO₂ nanoparticles improved the mechanical, nuclear shielding and structural properties of composites. The best gamma ray shielding competency has been showed by the highest TiO₂ addition (20%) composite. All in all, UPR + TiO2 composites have been identified as promising alternative radiation shielding candidates owning to their cost effectiveness, ease of processing, good dispersion and lightweightness.

Utilizing of Magnetized Water in Enhancing of Volcanic Concrete Characteristics

Volcanic concrete is an eco-friendly concrete type in that it contains coarse and fine aggregates that all extracted from the igneous volcanic rock. However, utilizing of volcanic ash (VA) as partial/full replacement of concrete cement significantly affects the concrete workability, especially at high cement replacement ratios. This has also some adverse effects on concrete strength. Utilizing magnetized water (MW) in concrete as a partial/full replacement of ordinary tap water (TW) has a notable effect on enhancing the fresh and hardened concrete properties. This research aims to study the effect of using MW prepared in a magnetic field of 1.4 Tesla on the workability and hardened properties (compressive, tensile, and flexural strengths) of volcanic concrete. In this study, VA partially replaced volcanic concrete cement with ratios of 5%, 10%, 15%, and 20%. Ten volcanic concrete mixes were prepared in two groups. The first one was prepared with VA (0–20%) and mixed with TW. The other group was prepared with the same VA contents like group one, but mixed with MW. Microstructure imaging for volcanic concrete was also conducted in this study. Results of water tests showed 17% and 15% increase in total dissolved solids (TDS) and pH, respectively, of MW compared with those of TW. In addition, the water magnetization decreased the water surface tension by 7% compared with that of TW. Results of hardened concrete tests showed that the best ratio of VA in volcanic concrete was 5% with and without using magnetized water. The volcanic concrete slump decreased when using TW; however, using MW enhanced the volcanic concrete slump by up to 8%. The compressive strength was improved by 35%, 23%, and 20% at 7 days, 28 days, and 120 days, respectively, with no VA and with the presence of MW. The compressive strength was improved by 11%, 12%, and 11% after 7 days, 28 days, and 120 days, respectively, with using 5% VA and with the presence of MW. Both splitting tensile strength and flexural strength of volcanic concrete with and without VA or MW behaved similar to that of the corresponding compressive strength.