M.Sc Student | Prilutskiy Zakhar |
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Subject | Determination of Concrete Composition Using Gamma-Ray Spectrometry |
Department | Department of Civil and Environmental Engineering | Supervisor | Professor Konstantin Kovler |
Full Thesis text | ![]() |
The information about concentrations
of natural radionuclides in concrete mix and mineral raw materials used for
concrete manufacture can be helpful for determination of concrete composition.
The present research deals with the development of the experimental method
based on gamma-ray spectrometry for controlling concrete composition of fresh
and hardened mixes. Ordinary Portland cement CEM-I 52.5N, manufactured
by Nesher - Israel Cement Enterprises Ltd, was used for all concrete mixtures.
The coal fly ash was obtained from the Orot Rabin power station. The local aggregates of three
categories were used - coarse, intermediate and fine (sand). Fresh concrete
mixes were cast in Polyethylene Marinelli beaker with a volume of 1 liter and
sealed immediately. Cast concretes were measured in different ages: from
several hours to half a year. To compare the results of the radioactivity
measurements, at the age of 28 days from the cast concrete cubes were crushed
and sealed in Marinelli beakers. The activity concentrations of 226Ra,
232Th and 40K in the raw materials and concrete were
measured using scintillation gamma-ray spectrometer equipped with the scintillation
NaI(Tl) detector. The measurement results and their accuracy were compared for
two types of gamma-ray spectrometers, with semiconductor high purity germanium (HPGe)
and scintillation detectors, while the HPGe measurements were made in
Ben-Gurion University. To study the effects of disequilibrium in the 226Ra
decay chain and radon diffusion through the Marinelli beaker walls, which accompany
the gamma spectrometry measurements, the additional tests were performed. In particular, 222Rn leakage from Marinelli
beakers and different containers were determined.