Synthesis and characterization of hydrogarnet Ca&lt;SUB&gt;3&lt;/SUB&gt;(Al&lt;SUB&gt;x&lt;/SUB&gt;Fe&lt;SUB&gt;1 - x&lt;/SUB&gt;)&lt;SUB&gt;2&lt;/SUB&gt;(SiO&lt;SUB&gt;4&lt;/SUB&gt;)y(OH)&lt;SUB&gt;4(3 − y)&lt;/SUB&gt;

Dilnesa, Belay Zeleke; Lothenbach, Barbara; Renaudin, Guillaume; Wichser, Adrian; Kulik, Dmitrii

doi:10.1016/j.cemconres.2014.02.001

Synthesis and characterization of hydrogarnet Ca₃(Al_xFe_{1 - x})₂(SiO₄)y(OH)_{4(3 − y)}

Dilnesa BZ, Lothenbach B, Renaudin G, Wichser A & Kulik D

Citation

Dilnesa, B. Z., Lothenbach, B., Renaudin, G., Wichser, A., & Kulik, D. (2014). Synthesis and characterization of hydrogarnet Ca₃(Al_xFe_{1 - x})₂(SiO₄)y(OH)_{4(3 − y)}. Cement and Concrete Research, 59, 96-111. https://doi.org/10.1016/j.cemconres.2014.02.001

Persistent URL https://www.dora.lib4ri.ch/empa/islandora/object/empa:6160

C₃AH₆ is a stable phase in the CaO–Al₂O₃–H₂O system at temperatures 20 °C and above. The presence of SiO₂ results in the formation of C₃AH₆ and C–S–H phases at room temperature. At 110 °C crystalline C₃AS_yH_2(3 − y) phases form. Two solid solutions: C₃AH₆–C₃AS_0.41H_5.18 and C₃AS_0.84H_4.32–C₃AS₃ are found with log K_s0 = − 20.50, − 25.35, − 26.70 and − 39.7 at 20 °C, respectively. In the CaO–Fe₂O₃–H₂O system, only traces of C₃FH₆ and C₄FH₁₃ phases are formed due to the high stability of FH phase. The presence of silica leads between 20 and 110 °C to the formation of C₃FS_0.84H_4.32 and C₃FS_1.34H_3.32 phases with log K_s0 = − 32.50 and − 34.20 at 25 °C. No significant solid solution formation occurred between C₃AH₆ and C₃FH₆ end members, but between C₃AS_0.84H_4.32 and C₃FS_0.84H_4.32 solid solution formation is observed. The determined solubility products indicate that C₃FS_0.84H_4.32 is the most stable iron-containing phase in hydrated Portland cements.