Durability and performance of Alkali-Activated Materials in extreme environments

Alkali-activated materials (AAMs) have been considered as sustainable alternatives to ordinary Portland cement (OPC), offering superior mechanical properties and chemical degradation resistance. Their potential applications in extreme environments, including aggressive chemical exposure and particularly irradiation exposure, have attracted significant research interest. This study aimed to evaluate the performance of AAMs under severe conditions in the context of nuclear-related applications. The irradiation resistance of AAMs was assessed, highlighting their ability to maintain mechanical strength and microstructural integrity under severe conditions (high gamma dose of 4032 kGy) compared to OPC. Their resistance to chemical degradation, including accelerated carbonation (60% RH, 1% CO2) and leaching (6 M NH4NO3), was also examined. Microstructural and mineralogical analyses, including X-ray diffraction, Fourier-transform infrared spectroscopy, mercury intrusion porosimetry, and nitrogen adsorption, were employed to understand the phase evolution and structural alteration of AAMs under these extreme conditions. The findings of this study highlight the promising applications of AAMs in specific nuclear-related structures, including radioactive waste immobilization, with a high waste loading of up to 25 vol. % organic waste. By utilizing the residual waste, these materials provide a sustainable and environmentally friendly approach. However, challenges remain in ensuring long-term performance, establishing standardized testing protocols, and scaling up production for broader applications.