Marine Geo-Polymer Cement Treated with Seawater, Alkaline Activators, Recycled Particles from Paste, and Recycled Particles from Glass

This study aims to develop the marine geo-polymer cement that was produced with seawater, recycled particles from paste, recycled particles from glass, and alkaline activators, including NaOH or Na₂O·3.3SiO₂. The physicochemical properties and strength of MGPC were investigated with a Uniaxial Compression Test, Particle Size Analysis, Energy Dispersive Spectrometer, X-ray Diffraction, and Thermal-field Emission Scanning Electron Microscopy. The results indicated that the main hydration products in MGPC were calcium carbonate (CaCO₃), silica (SiO₂), sodium aluminosilicate hydrate (Na₂O·Al₂O₃·xSiO₂·2H₂O, N-A-S-H), and aluminum calcium silicate hydrate (CaO·Al₂O₃·2SiO₂·4H₂O, C-A-S-H). The calcium carboaluminate (3CaO·Al₂O₃·CaCO₃·32H₂O, CO₃-AFm) in MGPC was converted into CaCO₃ and Friedel's salt (3CaO·Al₂O₃·CaCl₂·10H₂O), which prompted the carbon sequestration. The microstructure of MGPC prepared using Na₂O·3.3SiO₂ was based on RPG as the matrix, with N-A-S-H, C-A-S-H, and fibrous AFt growing on the periphery. This structure reduces the impact of the alkali-silica reaction on the material and improves its compressive strength. Therefore, the MGPC developed in this study shows the exact benefits of freshwater and natural minerals saving, carbon sequestration, and damage resistance.