Rehabilitation of Buildings Polluted by the Radon Radioactivity
Mario Collepardi, Silvia Collepardi, Roberto Troli
Appears on pages(s):
Radon gas; Bitumen-based radon gas barrier; Rehabilitation of polluted buildings due to radon gas.
Radon is a radioactive invisible, odorless, tasteless gas that seeps up through the ground and diffuses into the air. Radon gas naturally moves into the permeable soil and gravel bed surrounding foundations and then, inside the buildings through openings, cracks, and pores of the concrete. The type of constructions more exposed to the radon risk emanated from the ground are industrial buildings, supermarkets, shops, restaurants, and all the residential buildings where people work or live on the ground floors. In the present paper, the rehabilitation of building polluted by radon gas has been studied. Two techniques can be adopted to reduce the radon concentration in the building environments: A) change of the environmental air opening doors and windows of the building; B) if the change of air is incompatible with the industrial activity carried out in the building the radon entry can be blocked using the application on the existing concrete surface of a specific cap sheet membrane; in particular a bitumen-based radon gas barrier has been examined already studied and acting as an effective radon gas barrier. In the end, the radon barrier can be covered by a concrete layer. According to the Italian Legislative Decree No. 101/2020 presently the radioactivity caused by the radon gas in the houses and industrial buildings must be lower than 300 Bq/m3, whereas for the building erected after December 31, 2024, should be lower than 200 Bq/m3.