In this research, metakaolin-based geopolymers were synthesized to study their deterioration in marine environment. The geopolymers were exposed in air, seawater, dry-wet and heat-cool cycles of seawater for 30, 60 and 90 days. The mechanical property of the geopolymers was characterized through compressive strength measurements, and their microstructures were measured by X-ray diffraction (XRD), scanning electron microscope (SEM) and nuclear magnetic resonance (NMR) apparatus. It was found that seawater environment inhibited the geopolymerization reactions, so that a low amount of tetrahedral silicon of Q4(4Al), Q4(3Al) and Q4(2Al) were formed.
Li, X., Rao, F., Song, S., & Ma, Q. (2019). Deterioration in the microstructure of metakaolin-based geopolymers in marine environment. Journal of Materials Research and Technology, 8(3), 2747–2752. https://doi.org/10.1016/j.jmrt.2019.03.010