Synthesized CSC (Calcium Silicate Clinker: C₃S 70% and C₂S 30%) was hydrated in water as a control, and alkaline solutions: NaOH or KOH (5 M). The hydration kinetics was characterized by isothermal calorimetry. Hydrated samples after 28 days of curing were characterized by XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy) and SEM (Scanning electron microscopy). The results showed that the contact of synthesized phases with the liquid phase during hydration is affected by the presence of alkalis. The hydration of CSC in presence of alkalis leads to the acceleration of hydration and penetration of Na+ and K+ into the C-S-H structure, leading to the stimulation and generation of C-(N)-S-H and C-(K)-S-H. SEM observations revealed a significant difference in the morphology and composition of C-S-H in the presence of NaOH or KOH. The chemical activation of calcium silicate phases can be a promising solution to increase the hydraulic and mechanical properties of the resulting cementitious products.

PDF (Download Full text)

| Download Citation (XML)