Authors:
Manal Abdallah; Walaa Al-Tamimi; Ahmad Salameh; Sajedah Alamir;
Abstract:
Recently, our life is unavoidably exposed to radiation from various sources (natural and artificial). Cement is one of the most common used materials in buildings and decorations by people all over the world. This work examined the performance and potential radiological risks of natural radioactivity in cements used in Jordan. The results showed that all cement types were compliant with the Jordanian standard specifications (JSS. 30-1/2007) and European standards (EN. 19- 1/2000). The maximum value of compressive strength was 350.2 kg/cm2 in White Portland Cement (WPC type I 52.5N). Heat of hydration for all samples occurred between 330 min and 500 min from the moment of adding water, and heat released with approximate same rate values. The activity concentrations of 226Ra, 232Th, and 40K were detected in all cement samples. The maximum value of the activity concentrations (in Bq/kg ± SD) of 226Ra was 79.52 ± 4.67, while for 232Th and 40K were 30.99 ± 2.85, and 354.70 ± 19.64, respectively. The highest value of the dose rate was 117 ± 8 nGy/h. The annual effective dose due to absorption and Radium equivalent crest values were 574 ± 8 μSv/h and 343 ± 16 Bq/kg, respectively. The obtained results of external hazard, activity concentration index, and alpha index were less than unity for all samples. All measurements and calculations were within the recommended values except the dose rate value for two samples lapelled by S3 & S5. The results were compared with other studies from different countries all over the world.
Keywords:
Natural Radioactivity, Cement, Gamma ray spectroscopy, Radiation hazard parameters, heat of hydration, compressive strength.