Abstract：
Assessing the radon activity that exhales from building structures is crucial to identify the best strategies to prevent radon from entering a building or reducing its concentration in the inhabited spaces. The direct measurement is extremely difficult, so the common approach has consisted in developing models describing the radon migration and exhalation phenomena for building porous materials. However, due to the mathematical complexity of comprehensively modelling the radon transport phenomenon in buildings, simplified equations have been mostly adopted until now to assess the radon exhalation. A systematic analysis of the models applicable to radon transport has been carried out and it has resulted in four models differing in the migration mechanisms - only diffusive or diffusive and advective - and the presence of inner radon generation. The general solutions have been obtained for all the models. Moreover, three case-specific sets of boundary conditions have been formulated to account for all the actual scenarios occurring in buildings: both perimetral and partition walls and building structures in direct contact with soil or embankments. The corresponding case-specific solutions obtained serve as a key practical tool to improve the accuracy in assessing the contribution of building materials to indoor radon concentration according to the site-specific installation conditions in addition to the material inner properties.
摘要：
评估从建筑结构中呼出的氡活动对于确定防止氡进入建筑物或减少其在有人居住空间中的浓度的最佳策略至关重要。直接测量是极其困难的，因此，常见的方法包括开发描述构建多孔材料的氡迁移和呼气现象的模型。然而,由于全面模拟建筑物中氡运移现象的数学复杂性，到目前为止，大多数都采用简化方程来评估氡析出。对适用于氡运移的模型进行了系统分析，结果产生了四种不同的模型——只有扩散或扩散和对流——以及内部氡生成。已获得所有模型的一般解。此外，已制定了针对特定情况的三组边界条件，以说明建筑物中发生的所有实际情况：外围墙和隔墙以及与土壤或路堤直接接触的建筑物结构。获得的相应的特定案例解决方案可作为关键的实用工具，可根据特定地点的安装条件以及材料的内部特性，提高评估建筑材料对室内氡浓度的贡献的准确性。
