This paper investigates the effects of gamma radiation for energies of 0.66, 1.17, and 1.33 MeV on the mechanical and physical properties of normal weight concrete and heavyweight concrete in addition to investigating the possibility of replacing steel bars with carbon glass fiber reinforced polymer bars. Four concrete mixtures were designed to cover the research objectives using 112 standard cubes, 108 cylinders, steel bars, and carbon glass fiber bars. These concrete mixtures were tested for their compressive strength, splitting tensile strength, and bond strength. The relationship between specimen thickness and transmission of the rays was formed by affirmation of their mean free path, half-value layer, and tenth-value layer. Also, a tensile strength test was carried out for steel and carbon glass fiber bars before and after radiation exposure. The results indicated that the use of heavyweight concrete embedded in a certain proportion of barite and ilmenite is better than normal weight concrete in radiation properties, also it's concluded that carbon glass fiber bars could be used instead of steel bars in structures exposed to gamma radiations safely.