Microscopic Evaluation of Alkali-Silica Reactivity of Photovoltaic Panel Glass and ASR Suppressing Effect of Fly Ash

In this study, the characteristics of the alkali-silica reaction (ASR) of glass cullet and the effect of fly ash on suppressing ASR were investigated by microscopic observation for the purpose of recycling glass cullet obtained by crushing the glass of photovoltaic panels as fine aggregate. As a result, it was shown that ASR can be effectively suppressed by replacing high-quality fly ash with 15% or more of cement for glass cullet, which exhibits high alkali-silica reactivity. Furthermore, chemical compositions were compared by SEM-EDS composition analysis of the reaction layer of the glass interface, the pozzolanic reaction layer of the fly ash, and the ASR gel. As a result, it was found that the chemical composition of the reaction layer of the glass interface and the pozzolanic reaction layer of the fly ash were similar and the calcium oxide contents was high. In comparison, the chemical composition of ASR gel was found to be high in silica and sodium oxide contents.