In this study, geopolymer specimens based on calcined oil-contaminated clays (OCCs), metakaolin replacements of OCCs, and blast furnace slag were manufactured by the addition of nano-SiO2 to improve their properties. The effects of adding 0, 1, 2, or 3% nano-SiO2 on the properties and microstructures of the geopolymer specimens were determined using compressive strength tests, flow tests, setting time tests, scanning electron microscopy (SEM), and silicon nuclear magnetic resonance spectroscopy (Si-NMR). The results showed that the setting time and flowability of the geopolymer specimens decreased and the compressive strength increased as the amount of nano-SiO2 increased. These results were supported by the SEM and Si-NMR assays. This study suggests that the addition of nano-SiO2 was beneficial and improved the properties of the geopolymer specimens containing calcined OCC.
Keywords: Geopolymer; metakaolin; nano-material; oil-contaminated clay.