Phosphogypsum utilization in fired bricks: Radioactivity assessment and durability

This paper presents results in a room constructed using fired bricks made partly with phosphogypsum. Radon-222 concentration values are monitored and reported for two different seasons using a passive method (LR-115 dosimeters) and an active method (AlphaGuard) in spring season 2008 and using an active method the pulse type ionization chamber A1phaGUARD in the winter season of 2017. The average values obtained with the LR-115 in spring season 2008 are of 29 Bq/m(3) in finished normal room and 32 Bq/m(3) in finished phosphogypsum room. The average values obtained with active method at spring season 2008 in normal room and phosphogypsum room are 42 Bq/m(3) and 34 Bq/m(3), respectively. The average values in winter season 2017 are 20 Bq/m(3) and 15 Bq/m(3), respectively. This paper compares the measurement of indoor radon using a passive method and an active method for two different seasons and for two types of construction material. Meteorological factors such as temperature, barometric pressure and humidity were measured in order to study their influence on radon emanation. The results were presented for a reference room that was built with standard bricks with those an experimental room that was built with phosphogypsum containing brikd. Both rooms have the same physical characteristics. The measurements were made at the same time and under the same conditions. The study is focused on formulation, manufacturing process and characterization of the bricks. The new bricks meet all physical and mechanical requirements for this type of material. The results are very promising. All radon concentration values are below the strictest standards, i.e., less than 150 Bq/m(3) according to Canadian standards.