Masters Theses


Raul Florez

Keywords and Phrases

Linear Attenuation Coefficient; Magnetite; MCNP; Portland Cement; Radiation Shielding; Samarium Oxide


"Developing new cement based materials with excellent mechanical and attenuation properties is critically important for both medical and nuclear power industries. Concrete continues to be the primary choice material for the shielding of gamma and neutron radiation in facilities such as nuclear reactors, nuclear waste repositories, spent nuclear fuel pools, heavy particle radiotherapy rooms, particles accelerators, among others. The purpose of this research was to manufacture cement pastes modified with magnetite and samarium oxide and evaluate the feasibility of utilizing them for shielding of gamma and neutron radiation. Two different experiments were conducted to accomplish these goals. In the first one, Portland cement pastes modified with different loading of fine magnetite were fabricated and investigated for application in gamma radiation shielding. The experimental results were verified theoretically through XCOM and the Monte Carlo N-Particle (MCNP) transport code. Scanning electron microscopy and x-ray diffraction tests were used to investigate the microstructure of the samples. Mechanical characterization was also performed by compression testing. The results suggest that fine magnetite is a suitable aggregate for increasing the compressive and flexural strength of white Portland cement pastes; however, there is no improvement of the attenuation at intermediate energy (662 keV). For the second experiment, cement pastes with different concentrations of samarium oxide were fabricated and tested for shielding against thermal neutrons. MCNP simulations were used to validate the experimental work. The result shows that samarium oxide increases the effective thermal cross section of Portland cement and has the potential to replace boron bearing compounds currently used in neutron shielding"--Abstract, page iv.


Alajo, Ayodeji Babatunde
Castano Giraldo, Carlos Henry

Committee Member(s)

Colorado, Henry


Nuclear Engineering and Radiation Science

Degree Name

M.S. in Nuclear Engineering


Missouri University of Science and Technology

Publication Date

Summer 2016

Journal article titles appearing in thesis/dissertation

  • Mechanical behavior and gamma ray attenuation properties of magnetite-cement composites
  • Neutron attenuation properties of cement pastes modified with samarium oxide (SM2O3)


xi, 71 pages

Note about bibliography

Includes bibliographical references.


© 2016 Raul Fernando Florez Meza, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Cement composites -- Mechanical properties
Mass attenuation coefficients
Portland cement
Shielding (Radiation)
Monte Carlo method

Thesis Number

T 10953

Electronic OCLC #