Influence of Concrete Characteristics on Radon Transport

In order to achieve a fair description of radon transport through concrete certain information is needed on the concrete structure, porosity and permeability, on processes causing the transport of radon, on radon’s interaction with environment, factors favouring the generation of radon, etc. The concrete characteristics (that depend on its composition and especially on the W/C ratio) which influence the transport of radon through concrete are, mainly, porosity, permeability, diffusion, humidity and density. This paper presents the influence of W/C ratio and concrete density on apparent and overall porosity of concrete, permeability coefficient and diffusion coefficient. Also, we present influence of concrete permeability on the diffusion coefficient for many types of concrete prepared with different blended cements. The results achieved confirm the quality of concretes prepared with cements with slag, even if results achieved for slag in radioactive contents did not anticipate this. Concretes prepared with cement with slag addition are less permeable to air and water, display a lower porosity compared to other concrete types surveyed. A highly important parameter in the relation concrete radon is the water / cement ratio, a ratio that influences the concrete characteristics and implicitly the radon concentration within buildings.