Hydraulic activity and microstructural characterization of new fly ash-belite cements synthesized at different temperatures

The influence of the synthesis temperature of a new fly ash-belite cement ( FABC) on its hydraulic activity and microstructural characteristics is disc ussed in this work. Three types of FABC were synthesized at 700, 800, and 9 00 degrees C after a previous hydrothermal treatment at 200 degrees C of th e fly ash, CaO, and water mixture. The hydraulic activity of the pastes was evaluated during a period of 200 days from mixing through the combined wat er content, previously determined from thermogravimetric analyses, and the hydration advance degree by x-ray diffraction (XRD). The microstructure cha racterization of the pastes was studied by scanning electron microscopy (SE M).