Radiation shielding properties of heavy-weight concrete and heavy-weight geopolymer concrete incorporating nano-ZnS

The population growth and the subsequent increase in energy demand for buildings require the widespread use of sustainable materials in the construction industry. Therefore, geopolymer concretes (GPC) are expanding with the ability to emit less greenhouse gases (GHG) compared to conventional concrete. In this study, the effect of adding different content of Zinc sulfide nanoparticle (nano-ZnS) 0, 1.5, 3, 4.5, and 6 % by weight of cement on density (rho), compressive strength, gamma ray radiation protection characteristics, and microstructure based on scanning electron microscope (SEM) is investigated in heavy-weight concrete (HWC) and heavy-weight geopolymer concrete (HGC). The results have shown that nano-ZnS nanoparticles improve the strength and gamma ray shielding properties of HWC and HGC by modifying the microstructure so that by adding the optimal amount of 6 % nano-ZnS, the maximum compressive strength for HWC and HGC was obtained by 57.4 and 41.5 %, respectively. In addition, the highest linear attenuation coefficient (mu )was obtained with the addition of 4.5 % nano-ZnS for HWC and HGC, 12.8 and 8.9 %, respectively. Furthermore, the life cycle assessment (LCA) of the three phases of raw material production, transportation and concrete production has revealed that HGC has emitted 41.5 % less CO2 compared to HWC. In general, HGC in the presence of the optimal amount of nanoparticles has shown a more visible improvement in compressive strength and gamma ray shielding properties. In addition, HGC as an environmentally friendly material, has significantly reduced the emission of CO2.