Preparation and Characterization of Portland Cement Pastes with Sm₂O₃ Microparticle Additions for Neutron Shielding Applications

Abstract

Mechanical, microstructural and neutron attenuation properties of white ordinary Portland cement (WOPC) pastes with Sm2O3 additions ranging from 2.5 to 20 wt% are reported. Scanning electron microscopy (SEM) micrographs revealed that incorporation of Sm2O3 above 10 wt% enhance the formation of ettringite and increase the porosity of the cement composites. Microcracks were also observed in SEM images for compositions containing 20 wt% Sm2O3. X-ray diffraction (XRD) analysis determined that samarium oxide particles did not interact chemically with the cement matrix to form new crystalline phases. On the other hand, neutron transmission experiments and Monte Carlo simulations showed that the attenuation of thermal and epithermal neutrons increased significantly with the addition of Sm2O3. Maximum enhancement in neutron shielding was obtained for specimens loaded with 20 wt% Sm2O3, which have an effective removal cross section of Σeff=4.018cm-1 compared to Σeff=0.515cm-1 for plain WOPC paste.

Department(s)

Nuclear Engineering and Radiation Science

Keywords and Phrases

Concretes; Intelligent systems; Mechanical properties; Microcracks; Microstructure; Monte Carlo methods; Neutron emission; Portland cement; Radiation shielding; Scanning electron microscopy; X ray diffraction analysis; Crystalline phasis; Effective removals; Neutron attenuation; Neutron shielding; Neutron transmission; Ordinary Portland cement; Portland cement paste; Samarium oxides; Samarium compounds; Samarium oxide (II)

International Standard Serial Number (ISSN)

0950-0618

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2018 Elsevier, All rights reserved.

Publication Date

01 Aug 2018

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