Cimento alcalino a partir de resíduos de vidro de módulos fotovoltaicos e cal hidratada de casca de ostra

Abstract

With the advancement of photovoltaic technology and the absence of guidelines for the disposal of electronic waste, photovoltaic modules will be a common waste in landfills. In search of alternatives for valuing this material, the study developed a new alkaline cement using the photovoltaic modules glass (PMG), combined with hydrated oyster shell lime (HOSL) and an alkaline solution of sodium hydroxide (NaOH). This study investigated the formation of cementing gels over the curing time, considering different alkali contents and mechanical strengths, reporting the intrinsic chemical and molecular properties. For this, the unconfined compressive strength (UCS) and the relationship between theoretical porosity/lime content were evaluated through a detailed statistical analysis. In addition, an in-depth analysis by Fourier transform infrared spectroscopy (FTIR) was conducted. The multivariate analysis (MANOVA) identified the PMG/HOSL ratio as the most influential variable on mechanical strength, while the univariate (ANOVA) highlighted the curing time as the most significant factor. Both analyses confirmed statistical significance (p < 0.05), indicating that ANOVA did not result in a false positive. The FTIR revealed interactions between the reactive compounds and the formation of C-S-H gels and amorphous silicates, whose structure was consolidated by the redistribution of water and the interaction of cations with reactive phases. The results indicate polymerization and hydration mechanisms that promote chemical and structural stability, offering relevant contributions to the development of alkali-activated materials.