title: Metakaolin as a radon retardant from concrete.
abstract: Granite aggregates are known to be the radon source in concrete. Recently, metakaolin has been introduced as a partial substitution of Portland cement to produce high strength concrete. It can effectively reduce the porosity of both the matrix and the aggregate/paste transition zone, which suggests its ability to retard radon emission from concrete aggregates. In the present work, radon exhalation rates from concrete cubes substituted with metakaolin were measured using charcoal canisters and gamma spectroscopy, and were considerably lower than those from normal concrete, by about 30%. The indoor radon concentration reduction is estimated as approximately 9 Bq m(-3) calculated using a room model, causing a 30% reduction in the indoor radon concentration and the corresponding radon dose. Therefore, metakaolin is a simple material to reduce the indoor radon concentration and the radon dose.
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowlxon Tong, Hong Kong.
authors.forename: B M F
authors.initials: BM
authors.lastname: Lau
authors.forename: R V
authors.initials: RV
authors.lastname: Balendran
authors.forename: K N
authors.initials: KN
authors.lastname: Yu
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D003198:Computer Simulation; D003252:Construction Materials / Q000032:analysis*; D008422:Materials Testing / Q000379:methods; D008962:Models, Theoretical; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011837:Radiation-Protective Agents / Q000737:chemistry; D011874:Radiometry / Q000379:methods; D011886:Radon / Q000032:analysis*
chemical_list: D000396:Air Pollutants, Radioactive; D011837:Radiation-Protective Agents; D011886:Radon