In a groundbreaking study published in Applied Sciences, Olga Kononova from the Mechanical and Biomedical Engineering Institute at Riga Technical University, Latvia, has shed new light on the potential of oil shale ash (OSA) as a reinforcing filler in construction materials. The research, which examined the elastic properties of epoxy and concrete composites reinforced with OSA, offers promising avenues for the energy sector to repurpose industrial waste while enhancing mechanical properties and promoting environmental sustainability.
The study, led by Kononova, focused on OSA, a byproduct of oil shale combustion in power plants. Since 2018, OSA has been reclassified from hazardous waste to a valuable resource, opening up new possibilities for its use in sustainable materials. The research delved into the effects of OSA on the elastic modulus of epoxy–OSA and concrete–OSA composites, revealing intriguing results.
For epoxy–OSA composites, the elastic modulus increased with higher concentrations of OSA, indicating that OSA can significantly enhance the mechanical properties of epoxy resin. However, the story is more complex for concrete–OSA composites. The compressive strength tests, conducted according to LVS EN 12390-3:2019 standards, showed a variable decrease in the elastic modulus across different strength classes as the OSA content increased.
Kononova explained, “The findings highlight the potential of OSA as a reinforcing filler in construction materials, promoting environmental sustainability by repurposing industrial waste while offering mechanical benefits.” This dual benefit—environmental and mechanical—could revolutionize the construction industry, particularly in regions where oil shale is a significant energy source.
The study also compared experimental results with theoretical models, including the rule of mixtures, finite element method (FEM), Mori–Tanaka method, and Halpin–Tsai method. The rule of mixtures and FEM generally overestimated the modulus for epoxy–OSA, whereas the Mori–Tanaka and Halpin–Tsai methods provided closer predictions. For concrete–OSA, the results were more nuanced, suggesting that simple averaging methods may not fully capture the behaviors observed experimentally.
The implications of this research are far-reaching. As Kononova noted, “These findings are critical for the development of more accurate predictive models and the optimization of OSA utilization in composite materials.” By repurposing OSA, the energy sector can reduce its carbon footprint and contribute to a circular economy, where waste is minimized, and resources are kept in use for as long as possible.
The study, published in Applied Sciences (Zinātnes un Tehnoloģijas), underscores the importance of continued research into the properties and applications of OSA. As the construction industry seeks more sustainable and efficient materials, the insights gained from this research could shape future developments in composite materials, paving the way for a greener and more resilient built environment.