Abstract: In this paper, the surface radon exhalation rate of autoclaved aerated blocks and concrete blocks was measured with activated carbon box method. The influence of sampling time and sample sealing method on the measurement results was studied. The experimental results show that different sealing materials have some influence on the experimental results, but there is no significant difference. The density of concrete blocks is high, the specific activity of radionuclides is much higher than that of autoclaved aerated blocks, and the radon excrete rate is relatively high. In practice, the results of surface precipitation of autoclaved blocks vary greatly with sampling time, while the results of concrete blocks are relatively stable. In summary, the activated carbon box method has the advantage of low cost, convenient operation and easy to use in large quantities, and has strong practicability for engineering testing.

Key words: radon exhalation rate, autoclaved aerated blocks, concrete blocks, activated carbon box method