Radiation exposure to zircon minerals in Serbian ceramic industries

The influence of building material structure on radon emanation

In this work, the radon emanation coefficients for selected building materials that are most often used in Serbia for covering floor surfaces (concrete, concrete screed, granite, glazed ceramic tiles, marble, roofing tile, and terrazzo tile) were determined, and the influence of the material structure on their values. The concentration of²²⁶Ra activity in the samples was determined using the gamma spectrometry method. Radon emanation was measured with the RAD7 device. The porosity of the samples was tested using mercury intrusion porosimetry and water absorption methods, and the structural analysis was performed using x-ray diffraction analysis and x-ray fluorescence analysis. The measured values of²²⁶Ra activity concentrations were in the range (4.93-298) Bq kg^-1, and the estimated values of the radon emanation coefficients were in the range (0.55-6.05) %. The obtained results indicate that the chemical and mineralogical composition, method of production, and the²²⁶Ra activity concentration have an influence on the emanation of radon from the material. No significant correlation was found between the radon emanation coefficient and the open porosity of the material, most likely due to the inhomogeneous presence of pores of different dimensions in the materials. It was established that the total value of the emanation coefficient depends on the emanation coefficient for pores ⩽100μm in size.