Estudo da emanação de radonio em amostras de concreto com composições diferentes

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The radon-222 is a noble radioactivity gas present in uranium-238 decay chain. The concrete components (cement and aggregates) have their raw materials extracted from crust that contains uranium as impurity. The 238U contained in these components will decay following its decay chain until 206Pb, passing by radon that can diffuse to indoor air of dwellings. The 222Rn emanation from concrete depends upon two factors: 226Ra content and diffusion length. The main objective of this work was to assess the influence of the concrete proprieties in radon emanation. For this purpose, it was carried out a systematic study about radon emanation from concrete samples that have different mix proportions and that were produced with different cement types. The 222Rn concentration was determined in sealed plastic chamber employing solid state nuclear track detectors (LR-11S). The mechanical strength, water absorption, sorptivity, porosity and air permeability of concrete were determined to obtain information about diffusion length. The 226Ra concentration was also determined. The results indicated positive correlation between radon emanation coefficient and water absorption, sorptivity, air permeability and pore diameter; and negative between radon emanation coefficient and compressive strength. After the result analysis, it is concluded that the hierarchical order of the properties that affected the radon emanation is: air permeability, pore diameter, porosity, and finally water absorption and sorptivity

ASSUNTO(S)

concreto detectores nucleares concreto - transporte radon

ACESSO AO ARTIGO

Documentos Relacionados