C-S-H seeding activation of Portland and Belite cements: An enlightening in situ synchrotron powder diffraction study

C-S-H seeding in Portland cements is well known from basic scientific works and field applications. Moreover, this activation approach could be beneficial for low-CO2 under development where a general drawback poor mechanical strengths during the first week of hydration. However, mechanistic understanding different processes taking place when still not developed. Here, we contribute to knowledge gap by studying one commercial cement two industrial-trial belite cements. Three admixtures are employed, viz. types triisopropanolamine as typical alkanolamine. A multitechnique employed including calorimetry, ultrasonic pulse velocity, thermal analysis Rietveld laboratory X-ray powder diffraction data. Chiefly, an situ synchrotron study has allowed mapping out evolution every crystalline phase. Furthermore, use internal standard permitted measure changes overall amorphous content. In nutshell, alite (phases) hydrations significantly accelerated three studied Conversely, sulphate aluminate phase dissolutions enhanced. Faster ettringite crystallisation contributes observed improved properties at early ages. synergistic effect between alkanolamine addition proved. The importance these findings possible acceleration hydration discussed.