Evaluation of technical and gamma radiation shielding properties of sustainable ultra-high performance geopolymer concrete

This study proposed to use barite-enhanced ultra-high performance geopolymer concrete (UHPGC) as the composite matrix to develop high-strength, cement-free, and sustainable radiation shielding materials. The physical properties, gamma ray attenuation capacity, microstructure, and environmental and economic impacts of prepared barite-enhanced radiation shielding UHPGC were determined and compared with normal concrete and ultra-high performance concrete (UHPC). The combination of steel fibers and barite aggregate increased the density of UHPGC, thereby enhancing its gamma ray attenuation capacity. Multi-scale gamma ray shielding simulation results demonstrated that although thickness was the more decisive factor of gamma ray attenuation capacity of composites, the enhancement of the shielding capacity of the material helps reduce the floor area and the cost of radiation shielding structure. The micro-analysis results revealed that barite-enhanced UHPGC exhibited compact microstructure and excellent interfacial performance. Furthermore, life cycle assessment results demonstrated that UHPGC was more suitable as a composite matrix than UHPC to develop sustainable and low-cost radiation shielding materials.