Title:
Effect of Carbonation on Radon Exhalation Rate in Concrete
Author(s):
Magnus J. Döse and Johan L. Silfwerbrand
Publication:
Materials Journal
Volume:
119
Issue:
3
Appears on pages(s):
67-78
Keywords:
building materials; carbonation; diffusion; health; radon gas exhalation; supplementary cementitious materials (SCMs)
DOI:
10.14359/51734603
Date:
5/1/2022
Abstract:
Crushed rock aggregates may lead to unhealthy concentrations of radon gas in concrete buildings. The radon exhalation rate is dependent not only on the concrete mixture but also on its microstructure. Carbonation changes the microstructure, and it also
influences the radon exhalation rate. With the guidance of the standard carbonation test, EN 12390-3:2019, and radon exhalation rate tests as specified in ISO-EN 1165-7, it is found that carbonation has a significant effect on the radon exhalation rate, being reduced by approximately 25% for ordinary portland cement (OPC) after carbonation. In concretes with a substitution of supplementary cementitious materials (SCMs), the radon exhalation rate increased by approximately 30% after carbonation. Conclusively, concretes containing OPC and concretes containing SCMs (fly ash and slag) showed opposite trends as a result of increased carbonation ingress into the concrete mixtures. Diffusion measurements of OPC concrete and concrete containing slag (SCM) support this hypothesis.