Aggregates grain size and press rate dependence of the shielding parameters for some concretes

This study points to evaluate the effect of crushed basalt grain size and the press rate on gamma ray shielding properties for some concretes. Nine different concretes were made up of 75% basalt, 25% Portland cement and drops of sodium meta silicate. Three concretes were performed with an average grain size varied between 25 and 107 mu m. The other six concretes were performed under different press rate varied between 1.01 and 142.76 kg/cm2 using a hydraulic press. The mass attenuation coefficient (mu m) of the prepared concretes was measured using the narrow beam transmission method using a hyper pure germanium detector at gamma ray energies 661.6, 1173.2, 1332.5, 121.8, 244.7, 344.3, 778.9, 964, 1112, 1408 KeV emitted by point sources Cs-137, Co-60 and Eu-152. Other important shielding parameters such as half value thickness and radiation protection efficiency were calculated for the prepared concretes at different energies. The obtained experimental data was compared with theoretical data obtained from XCOM program. The results showed that the mass attenuation coefficient was decreased with energy increase, but it increases with grain size decrease. The obtained results showed also that the mass attenuation enhanced by increasing the pressure rate.