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- ArticleYalnız künye2026Monitoring of the compatibility between the radon gas emanation and the self-compacting concrete properties using different mineral admixture
Bulut, H. Alperen; Şahin, Remzi
The relationships between radon gas emanation, permeability, and compressive strength in Self-Compacting Concretes containing different ratios of fly ash, silica fume, and ground granulated blast furnace slag (respectively of 5%, 12.5%, and 20%) were comprehensively investigated. Permeability tests were performed according to both traditional (sorptivity) and indirect (rapid chloride ion permeability) methods, and the relationship between Brunauer-Emmett-Teller analyses and radon concentration of self-compacting concretes was also analysed. Based on 120-day data, the optimum ratios for the combination of high compressive strength and low Average Radon Activity Concentration were determined to be 5% fly ash and 20% silica fume. As the sorptivity coefficients of self-compacting concretes containing silica fume and ground granulated blast furnace slag increased, the Average Radon Activity Concentration also increased. This later decreased with the increase in the sorptivity coefficient of the mixtures. The rapid chloride ion permeability of the control, fly ash-, ground granulated blast furnace slag-, and silica fume-added concrete was found to be 6077 Coulomb, 2989 Coulomb, 1668 Coulomb, and 1137 Coulomb, respectively. The relationship between rapid chloride ion permeability and Average Radon Activity Concentration of the mixtures varied depending on the type of mineral additive. The 90-day sample containing 12.5% fly ash had the highest Brunauer-Emmett-Teller surface area (33.01 m2/g) and cumulative pore volume (0.071 cm3/g) values. This study provides a novel perspective by simultaneously examining the relationships between radon activity concentration, permeability properties, and compressive strength of self-compacting concretes produced with different mineral additives. Unlike previous studies, this work establishes direct correlations between radon emanation and both sorptivity and chloride ion permeability, identifying silica fume and ground granulated blast furnace slag as effective additives for achieving low-permeability and low-radiation concrete. These findings offer a new approach for developing durable and radiologically safer self-compacting concrete mixtures.
RDL Kalıcı Kaydıİncele - Review ArticleAçık Erişim2024Radon, Concrete, Buildings and Human Health—A Review Study
Bulut, H. Alperen; Şahin, Remzi
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.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2023Activity concentration and annual effective dose assessments of radon in SCCs with different mineral additives
Alperen Bulut, H.; Şahin, Remzi
This study was conducted to investigate the hypothesis that radon gas emanation which is harmful to human health may occur more than standard values in Self-Compacting Concrete (SCC) which has a higher amount of dust material than conventional concretes. The SCCs with 5 %, 12.5 %, and 20 % fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBFS) as well as control concretes without mineral additives were placed closed glass environments with dimensions of 150×150×150 mm; average radon activity concentrations (ARACs) were measured passive method by CR-39 nuclear trace detectors after 7–14-21–28-56–90 and 120 days. Radioactivity analyses including annual effective equivalent dose (AEED) calculation of the concretes were also done. The ARAC values of SCCs increased significantly along with the increase of FA and decreased significantly with the increase of SF. So that the ARAC value (131.56 Bq/m3) of SCC with 20 % FA increased 2.40-fold when compared to the control concrete; however, the ARAC value (14.22 Bq/m3) of SCCs containing 20 % SF was found 4.5-fold lower than the control concrete. 5 % of the concretes containing GGBFS reduced the radon gas emanation; however, the rates of 12.5 % and 20 % increased the emanation. The highest AEEDs for each mineral additive type were 7-day samples including 20 % of FA (8.00 mSv/year), 5 % of GGBFS (3.17 mSv/year) and 5 % of SF (2.16 mSv/year). 12.5 % and 20 % FA-added SCCs emit radon gas above the limit levels. The results have confirmed the hypotheses of the present research depending on the mineral additive type and rate.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022Radiological characteristics of Self-Compacting Concretes incorporating fly ash, silica fume, and slag
Bulut, H. Alperen; Şahin, Remzi
This article presents the results of a comprehensive study investigating the hypothesis that higher concentrations of natural radionuclides, that are harmful to human health, may be present in Self-Compacting Concretes (SCCs) due to its higher powder material content compared to conventional concretes. The fresh (slump-flow, T500 time, V-funnel) concrete and compressive strength of SCCs prepared by replacing Portland cement with fly ash (FA), silica fume (SF), and ground granulated blast furnace slag (GGBFS) in the respective range of 5%, 12.5%, and 20% were determined. The radionuclide activity concentration of all solid concrete components and SCCs were determined using the gamma spectrometry method. Radioactivity analyses including the calculation of the activity concentration index and annual effective dose equivalents were also performed. The findings showed that the specimens with the highest average compressive strength at the end of 120th day were, respectively, SF (54.2 MPa), FA (52.2 MPa) and GGBFS (46.1 MPa) added to the SCC. The obtained concentration of the Radium-226 value (41.1) of 20% UK with added SCC was 1.8 times higher than the control concrete (22.7) and 2 times higher than 20% SF added SCC (19.7). The highest Radium equivalent activity (Raeq) values were FA20 (89.52), GGBFS20 (72.05), control concrete (70.86) and SF20 (68.01). It was determined that the FA selected for the study exceeded the limit specified for structural material (3.38 > 1) and fell in the radiologically hazardous class. It has been proven that SF can be used as a radioactivity reducing material of concretes. The results revealed that the research hypothesis was confirmed in terms of FA.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2017A study on mechanical properties of polymer concrete containing electronic plastic waste
Bulut, H. Alperen; Şahin, Remzi
It is aimed to research the effects of electronic plastic waste (e-plastic) on the mechanical properties of polymer concrete. E-plastic was used as a part of the filling materials (quartz sand and gravel) to obtain polymer concrete in this study. Unsaturated polyester resin material has been chosen as the polymer material and used as binder in polymer concrete production. Resin/filling material ratio has been determined as 10–90%, 15–85% and 20–80%, e-plastic/filling material ratio has been decided to be 0%, 5%, 15% and 25%. 28-Day of axial compressive, flexural and splitting tensile strength values of the test samples were evaluated. The increase in the ratio of resin, increases the compressive strength while it does not cause a dramatic increase or decrease in the flexural and splitting tensile strength. Compressive, flexural and splitting tensile strength values decrease as the ratio of e-plastic increases. On the other hand, electronic plastic waste increases the polymer concrete's ductility. Experimental study shows that ideal resin ratio and ideal e-plastic ratio values are 15% and 5%, respectively.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2011Determination of transmission factors of concretes with different water/cement ratio, curing condition, and dosage of cement and air entraining agent
Şahin, Remzi; Polat, Recep; Içelli, Orhan; Çelik, Cafer
This study focuses on determination of transmission factors of main parameters affecting the properties of both normal- and heavy-weight concrete in order to increase knowledge and understanding of radiation attenuation in concrete at a later age. Water/cement (W/C) ratio, curing condition, cement quantity and air entraining agent (AEA) were selected as the main parameters. Eight energy values have been selected within the energy interval of 30.85-383.85 keV to be used in the radiation source. The Taguchi Method was used as the method of optimization. It was determined in the study that the most important parameter affecting the attenuation of the radiation of the concrete is the W/C ratio and the concretes produced with the lowest level of W/C ratio absorb more radiation. However, it was also determined that there was a combined effect between the W/C ratio and the cement dosage.
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