Laboratory Evaluation of Heavy Aggregate Concrete Containing Recycled Aluminum against Radiation

The use of medical equipment that generates harmful radiation, such as gamma rays, has become very common today. Therefore, engineers are striving to create conditions that, in addition to meeting architectural requirements, minimize the weight increase in structures and reduce the radiation transmitted from specialized rooms to the external and adjacent rooms. The use of high-density concrete can be a suitable solution. In this study, an attempt was made to design concrete mixtures using the Preplaced aggregate concrete (PAC) method, as well as the incorporation of two additives: Recycled Aluminum (RA) and hematite heavy aggregate, in five different mixture designs. The objective was to achieve not only adequate compressive strength but also a high specific gravity of the concrete while reducing the transmission of gamma rays to the surrounding environment. Tests were conducted on the specimens before and after exposure to gamma radiation for a ۲۸-day period, including attenuation coefficient and compressive strength tests. The results showed that gamma radiation had no significant effect on the compressive strength of the concrete specimens. However, replacing coarse aggregates with hematite resulted in approximately a ۲۰% increase in compressive strength and a ۱۴% increase in specific gravity. The gamma ray attenuation tests conducted at energy levels of ۶۶۲, ۱۱۷۰, and ۱۳۳۲ KEV on the specimens indicated that as the specific gravity of the samples increased, the attenuation coefficient increased, and the energy transmission decreased. Although the use of RA led to a decrease in compressive strength and had no significant effect on the specific gravity of the concrete, its incorporation in concrete structures is recommended against gamma radiation due to its ability to reduce energy transmission by approximately ۴۰% and increase the attenuation coefficient by approximately ۳۰%, which is a considerable and remarkable effect.

کلیدواژه ها:

Heavy concrete ، Preplaced aggregate concrete (PAC) ، Recycled aluminum (RA) ، Hematite ، Gamma radiation