Radiological characteristics of Self-Compacting Concretes incorporating fly ash, silica fume, and slag

Bulut, H. Alperen; Şahin, Remzi

doi:10.1016/j.jobe.2022.104987

Cited by 15 publications

(4 citation statements)

References 79 publications

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“…Granulated blast-furnace slag (GBFS) is obtained from iron ore, which may contain clayey material, limestones and dolomites (used as melting fluxes), and the sulfur ash from coke, used as blast-furnace feed [ 44 , 46 ]. The radioactive content of this type of material has been little studied and varies between 16.1 and 167 Bq kg −1 for 226 Ra, between 5.0 and 66.5 Bq kg −1 for 232 Th, and between 96.1 and 235.6 Bq kg −1 for 40 K [ 50 , 82 , 83 ]. The scores obtained in the HJ–Biplot ( Figure 5 ) showed, like the FA, high variability and were again close to the origin of the coordinates, showing little influence of the factors found by the PCA.…”

Section: Discussionmentioning

confidence: 99%

New Approach to Determine the Activity Concentration Index in Cements, Fly Ashes, and Slags on the Basis of Their Chemical Composition

et al. 2023

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The manufacture of Portland cement entails high energy and environmental costs, and various solutions have been implemented in recent years to mitigate this negative impact. These solutions include improvements in the manufacture of cement clinker or the use of supplementary cementitious materials (SCMs), such as fly ash (FA) or slag as a replacement for a portion of the clinker in cement. The incorporation of these SCMs in cement may increase its radiological content as they are naturally occurring radioactive materials (NORMs). The Activity Concentration Index (ACI) is a screening tool established in the European EURATOM Directive 2013/59 to determine the radiation protection suitability of a final construction material. The ACI is determined by the activity concentrations of 226Ra, 232Th and 40K, usually determined by gamma spectrometry. The methodology of gamma spectrometry is accurate and appropriate, but this technique is not available in all laboratories. For this reason, and taking into account that there is a relationship between the chemical and radiological composition of these building materials, a new approach is proposed to determine the radiological content of these materials from a chemical analysis such as X-ray fluorescence (XRF). In this paper, principal component analysis (PCA) is used to establish the relationships between the chemical composition and radiological content of cements, FAs, and slags of different natures. Through PCA it was possible to group the cements based on two variables: CaO content and Fe2O3–Al2O3–TiO2 content. A lower correlation was observed for the FAs and slags, as the sample scores were centered around the origin of the coordinates and showed greater dispersion than the cements. The clusters obtained in the HJ–Biplots allowed the determination, using multiple regression, of models relating the activity concentration of 226Ra, 232Th (212Pb), and 40K to the oxide percentages obtained for the three matrices studied. The models were validated using five cements, one FA and one slag with relative percentage deviations (RSD(%)) equal to or less than 30% for 89% of the activity concentrations and 100% of the ACI determined.

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Section: Discussionmentioning

confidence: 99%

New Approach to Determine the Activity Concentration Index in Cements, Fly Ashes, and Slags on the Basis of Their Chemical Composition

et al. 2023

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“…Therefore, awareness has been raised on the subject. At the end of these studies, it is stated that among the components that constitute concrete, the cement and mineral additives obtained as industrial by-products play a major role in radon gas emissions [47][48][49].…”

Section: Radonmentioning

confidence: 99%

“…Therefore, awareness has been raised on the subject. At the end of these studies, it is Buildings 2024, 14, 510 2 of 29 stated that among the components that constitute concrete, the cement and mineral additives obtained as industrial by-products play a major role in radon gas emissions [47][48][49]. Kovler [50] reported that fly ash has an increased concentration of Naturally Occurring Radioactive Materials (NORMs).…”

Section: Introductionmentioning

confidence: 99%

Radon, Concrete, Buildings and Human Health—A Review Study

Bulut,

Şahin

2024

Buildings

Self Cite

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A comprehensive evaluation of the results obtained according to the measurement of radon gas in buildings and concrete, which is the most consumed material in the world after water, in accessible studies carried out in the last 40 years is the main objective of this study. The paper additionally aims to address the gap in the literature by comparatively determining which parameters affect radon–concrete and radon–building relationships. The scientific knowledge compiled within the scope of this article was presented under the main headings of radon and radon gas measurements in concrete and buildings. Radon gas, also known as the “invisible killer”, is considered the second most important cause of lung cancer after smoking (the gas is responsible for 3–14% of lung cancer cases in the world). The results determined that radon concentration limits have been applied in the range of 100–400 Bqm−3 in houses and 100–3700 Bqm−3 in workplaces. Studies conducted on the exhalation rate of radon showed that the radon exhalation rate of concrete may be in the range of 0.23–510 Bqm−2 h−1. The results of indoor radon concentration measurements revealed that values between 4.6 Bqm−3 and 583 Bqm−3 were obtained. Despite the existing literature, some researchers state that there is an urgent need for an improved and widely accepted protocol based on reliable measurement techniques to standardize measurements of the radon exhalation rate of construction materials and the indoor radon concentration of buildings.

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“…Also, the person is exposed to the gamma radiation field produced by any vertical structural elements, in a distance that varies significantly by case (Figure 1). Many previous studies estimated ACI (or I γ index, as mentioned in some of them) or other similar indexes such as the 226 Ra equivalent activity concentration (Ra eq in Bq/kg) and the external hazard index (H ex , dimensionless as per ACI), when gamma radiation is assessed for concrete or even its constituents [16][17][18][19][20][21][22][23][24][25][26][27]. None of them have proposed a method according to the ISO approach to estimate the uncertainty of the results.…”

Section: Introductionmentioning

confidence: 99%

Activity Concentration Index Values for Concrete Multistory Residences in Greece Due to Fly Ash Addition in Cement

Gavela,

Papadakos

2023

Eng

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According to 2013/59/Euratom Directive, the activity concentration index (ACI) is required to be estimated for each building material that is of concern from a radiation protection point of view. This index applies to building materials and not to constituents that cannot be used as building materials themselves. Fly ash is a byproduct of coal-fired power plants and is one of the main constituents of cement. The radioactivity in fly ash that is produced by Greek lignite power plants cannot be considered insignificant. For example, in the case of the Megalopolis power plant, the concentration for radioisotopes of the 226Ra chain is found to be about 1 kBq/kg. Since natural radionuclide concentrations, which are harmful to human health in terms of radiation exposure, exist in fly ash, ACI should be assessed for building materials containing fly ash. The present study evaluates the ACI of concrete containing fly ash cement when used in multistory residential buildings. Results showed that cement produced in Greece by the three main Greek cement production plants, containing lignite fly ash, and used as a material for concrete multistory constructions, should not be considered as “of concern from a radiation protection point of view”. Each country that wishes to evaluate the use of fly ash into constructions should repeat the method for the ACI uncertainty budget proposed in this study, to assess whether it significantly exceeds the reference value (whether it is of concern from a radiation protection point of view).

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Radiological characteristics of Self-Compacting Concretes incorporating fly ash, silica fume, and slag

Cited by 15 publications

References 79 publications

New Approach to Determine the Activity Concentration Index in Cements, Fly Ashes, and Slags on the Basis of Their Chemical Composition

New Approach to Determine the Activity Concentration Index in Cements, Fly Ashes, and Slags on the Basis of Their Chemical Composition

Radon, Concrete, Buildings and Human Health—A Review Study

Activity Concentration Index Values for Concrete Multistory Residences in Greece Due to Fly Ash Addition in Cement

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