Naturally occurring radioactivity in some Swedish concretes and their constituents: Assessment by using I-index and dose-model
2016 (English)In: Journal of Environmental Radioactivity, ISSN 0265-931X, E-ISSN 1879-1700, Vol. 155-156, 105-111 p.Article in journal (Refereed) PublishedText
The reference level for effective dose due to gamma radiation from building materials and construction products used for dwellings is set to 1 mSv per year (EC, 1996, 1999), (CE, 2014). Given the specific conditions presented by the EC in report 112 (1999) considering building and construction materials, an I-index of 1 may generate an effective dose of 1 mSv per year. This paper presents a comparison of the activity concentrations of 4 0K, 226Ra and 232Th of aggregates and when these aggregates constitute a part of concrete. The activity concentration assessment tool for building and construction materials, the I-index, introduced by the EC in 1996, is used in the comparison. A comparison of the I-indices values are also made with a recently presented dose model by Hoffman (2014), where density variations of the construction material and thickness of the construction walls within the building are considered. There was a ~16-19% lower activity index in concretes than in the corresponding aggregates. The model by Hoffman further implies that the differences between the I-indices of aggregates and the concretes' final effective doses are even larger. The difference is due, mainly to a dilution effect of the added cement with low levels of natural radioisotopes, but also to a different and slightly higher subtracted background value (terrestrial value) used in the modeled calculation of the revised I-index by Hoffman (2014). Only very minimal contributions to the annual dose could be related to the water and additives used, due to their very low content of radionuclides reported.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 155-156, 105-111 p.
Aggregates, Building materials, Concrete, Construction product, Dose model, I-index, Radioactivity
Environmental Analysis and Construction Information Technology
IdentifiersURN: urn:nbn:se:kth:diva-186973DOI: 10.1016/j.jenvrad.2016.02.012ISI: 000374358100014ScopusID: 2-s2.0-84960957052OAI: oai:DiVA.org:kth-186973DiVA: diva2:929302
QC 201605182016-05-182016-05-162016-09-23Bibliographically approved