Radon emanation from concrete and the influence of using flyash in cement

Abstract

In the Netherlands both Portland cement and blast furnace cement (slags from blast furnaces with about 30% Portland cement) are used for concrete. Radon exhalation measurements were carried out on concrete blocks made with these two types of cement and blocks with 15, 25 and 35% of the cement substituted by three different types of flyash. The results show that substituting part of the cement by flyash has no drastic effect on the exhalation rate. For concrete with Portland cement the exhalation rate decreases using flyash with an average radium content. With blast furanace cement a slight increase may be expected. The exhalation of concrete is greater than the sum of the exhalation values of the constituting components. The water in the pores the concrete plays an essential role in the emanation processs.