Vol.:(0123456789) 1 3
Journal of Radioanalytical and Nuclear Chemistry
https://doi.org/10.1007/s10967-020-07250-1
Chemical, physical and radiological evaluation of raw materials
and geopolymers for building applications
Snežana S. Nenadović
1
· Claudio Ferone
2
· Miloš T. Nenadović
3
· Rafaele Ciof
2
· Miljana M. Mirković
1
·
Ivana Vukanac
4
· Ljijana M. Kljajević
1
Received: 6 March 2020
© Akadémiai Kiadó, Budapest, Hungary 2020
Abstract
The main goal of this study was the evaluation of physical–chemical, as well as radiological properties of residual materi-
als used for geopolymer synthesis and those fnal products as a possible application as new materials in a civil engineering
industry. Concentration of
40
K and radionuclides from the
238
U and
232
Th decay series in waste precursors, their metaphases
and geopolymer samples synthetized by alkali activation were determined together with corresponding absorbed dose rate
(
D) and the annual efective dose rate. Natural activity concentrations in the alkali-activated material (geopolymer) were
found to be lower than that of both residual materials and calcined ones.
Keywords Radionuclides · Clay sediments · Geopolymer · Building materials · XRD
Introduction
Over the last few decades, the interest in the radiological and
health impact of building materials has grown and encour-
aged research activities [1, 2]. The radiation of terrestrial
origin in buildings does not only originate from the soil, but
also from the used building materials [3], a greater absorbed
dose rate can be measured inside the buildings (world aver-
age 84 nGy h
−1
) than outdoors (59 nGy h
−1
) [4].
Naturally occurring radionuclides such as uranium,
radium and radon are distributed in very low concentrations
in the environment, migration can take place through difer-
ent media like water, air, rock and soil [5–10].
Several routes of exposure must be explored to assess the
impact of natural radionuclides in buildings on residents.
In addition to direct gamma radiation, an important route
of radiation exposure comes from radon, which originates
from building materials or soil. The results of various epi-
demiological studies show that there is a linear relationship
between dose and no-threshold efect (LNT hypothesis), as
for example between exposure due to radon and lung cancer.
International studies, performed by the World Health Organ-
ization (WHO) [11], showed that building materials have a
non-negligible share of radiation exposure of the public due
to radon. Depending on the material, the concentration of
natural radionuclides (mainly
226
Ra,
232
Th and
40
K) amounts
up to 4000 Bq/kg [12, 13]. The most recent legislation in
Europe about safety standards for the protection against the
dangers arising from the exposure to ionizing radiation is
the European Directive 2013/59 Euratom [14]. Many studies
have focused on the radioactivity of building materials in the
world, as many building materials contain more radioactive
elements than those occurring in nature. The most important
of these are
40
K and members of two natural radioactive
series, which can be represented by isotopes
232
Th and
238
U.
The presence of these radioisotopes in building materials
causes external exposure to people living in the home.
226
Ra
* Snežana S. Nenadović
msneza@vin.bg.ac.rs
1
Department of Material Science, „VINČA” Institute
of Nuclear Sciences - National Institute of the Republic
of Serbia, University of Belgrade, P.O. Box 522,
Belgrade 11001, Serbia
2
Dipartimento di Ingegneria, Università di Napoli
“Parthenope”, Centro Direzionale, Isola C4, 80143 Naples,
Italy
3
Department of Atomic Physics, „VINČA” Institute
of Nuclear Sciences - National Institute of the Republic
of Serbia, University of Belgrade, Belgrade, Serbia
4
Department of Radiation and Environmental Protection,
„VINČA” Institute of Nuclear Sciences - National Institute
of the Republic of Serbia, University of Belgrade, Belgrade,
Serbia