Novel Alkali-Activated Binder from Photovoltaic Module Glass and Oyster Shells: Insights into Mechanical, Chemical, and Molecular Properties

Abstract A novel alkali-activated binder was developed using processed glass from photovoltaic modules (PMG) and hydrated oyster shell lime (HOSL), and sodium hydroxide. The formation of cementitious gels was investigated over time, assessing the influence of alkali content on mechanical strength, chemical and molecular properties. Unconfined compressive strength test and Fourier-transform infrared spectroscopy were performed, supported by statistical analyses. PMG particles up to 850 μm showed evidence of surface dissolution, a behavior not previously reported. Hydration was dominated by C─S─H gel, with compositional changes observed after 28 days, including amorphous silica precipitation. After 63 days, redistribution of structural water and carbonate formation were identified. Compressive strength reached 2.88 MPa at a PMG/HOSL ratio of 4 and alkali concentration of 3 M. These findings underscore the potential of the novel binder for geotechnical applications, such as soil and tailings stabilization, and provide new insights into the hydration mechanisms in alternative binder.