1,720,971 research outputs found
Expectations and experiences regarding radiation protection during geothermal operation
No full textManaging NORM in geothermal installations
Introductory presentation for Workshop with invited representatives of authorities, experts and industry
Environmental impact assessment for the recycling of phosphogypsum in alternative cementitious binders
No full textEnvironmental impact assessment for the recycling of phosphogypsum in alternative cementitious binders
No full textWith the support of the
Fund Prof. T. Van Autenboer,
managed by the King Baudouin Foundation
Environmental impact assessment for the recycling of phosphogypsum in alternative cementitious binders
No full textWith the support of the
Fund Prof. T. Van Autenboer,
managed by the King Baudouin Foundation
Environmental impact assessment for the recycling of phosphogypsum in alternative cementitious binders
No full textExpectations and experiences regarding radiation protection during geothermal operation
No full textManaging NORM in geothermal installations
Introductory presentation for Workshop with invited representatives of authorities, experts and industry
Assessing the impact of phosphogypsum composition on radon exhalation from alkali-activated materials
No full textThis study assessed the influence of phosphogypsum (PG) composition on the immobilisation potential of 222Rn in alkali-activated materials (AAMs) made with ground granulated blast furnace slag (GGBFS). The elemental composition of PG varies according to the origin of the ore and the process used. To improve recycling of PG, the effect of varying elemental composition on binder properties and radon exhalation needs to be assessed. The matrix properties were altered by incorporating different types and concentrations of PG as dry precursor as well as by varying the molarity of the sodium hydroxide alkali-activator. The resulting alkali-activated binders were characterised using gamma-ray spectrometry, X-ray diffraction (XRD), radon exhalation, mercury porosity, and compressive strength measurements. The massic activities of 226Ra, 228Th, 228Ra, and 40K were used to determine the Activity Concentration Index (ACI) of the dry precursor mixtures. Qualitative analysis of XRD diffractograms revealed the presence of mainly ettringite, bassanite, vaterite, aragonite, gypsum, and calcite with varying peak intensities in the different binders compositions. Radon exhalation rates ranged from 8 mBq/(kg.h) to 182 mBq/ (kg.h), and these values were used to calculate the radon emanation coefficient. An increase in the PG/GGBFS ratio was associated with a reduction in total mesoporous and microporous surface area. Additionally, higher PG content in the dry precursor mix resulted in a more consistent stabilisation of compressive strength with values ranging from 15 MPa to 20 MPa. These findings highlight a novel route to reduce radon exhalation while valorising an industrial by-product. By showing that PG incorporation both densifies the AAM matrix and sustains strength, this work provides a practical framework for developing safer, radiation-aware building materials.Funding
This project has received funding from the Euratom research and training programme 2019–2020 under grant agreement No 900009 (RadoNorm) and runs under the Collaborative Doctoral Partnership between JRC and UHasselt, agreement number 35,342. Support for this work was provided by the King Baudouin foundation [project 2020- E2141050-E001].
Acknowledgement
This project has received funding from the Euratom research and training programme 2019–2020 under grant agreement No 900009 (RadoNorm) and runs under the Collaborative Doctoral Partnership between JRC and UHasselt, agreement number 35342. Support for this work was provided by the King Baudouin foundation [project 2020- E2141050-E001]
Bridging barriers to enable recycling of phosphogypsum in alternative cementitious binders
No full textThe recycling of phosphogypsum (PG) in construction materials represents a multidisciplinary challenge where technical, radiological, chemical and stakeholder perception related barriers need to be overcome. From the 215 million-ton PG that is produced annually only 60-80 million ton is being recycled. In this context it is important to make a distinction between the recycling of the-often well controlled product-PG that is produced directly from industrial processes and the very heterogeneous PG that is present in landfills. [1] For the replacement of gypsum in different cementitious binders and concrete types, PG can be considered. Remaining traces of phosphoric acid, fluorides, metals, naturally occurring radionuclides, rare earth elements or organic substances in PG can however influence the mechanical properties of cementitious binders (e.g. delay in setting time, reduction in workability or strength), require additional measures for handling by construction workers or result in a negative environmental impact. [2] The current study takes a closer look at the different barriers that limit/inhibit the recycling of PG in alternative cementitious binders and concretes such as ettringite and alkali activated binders and concretes using these binders. The research needs and steps to overcome these barriers are discussed. The focus of the study is on recycling of PG in cementitious binders and concretes considering legislative (e.g. Euratom Basic Safety Standards (EU-BSS)), technical (focusing on mechanical properties), safety and environmental requirements (radiological and leaching properties) and considering the input from socioeconomic research on stakeholder perception and acceptance. The study aims to contribute to the construction of a strategic research road map identifying multidisciplinary research gaps regarding the use of naturally occurring radioactive materials in new cementitious binders and concretes.Support for this work was provided by the King Baudouin foundation
[project 2020-E2141050-E001
- …
