C-S-H based nucleation seed prepared from waste glass powder and carbide slag and its application in Portland cement

In this study, waste glass powder (GP) and carbide slag (CS) were attempted to prepare Nano C -S -H gel seed (NCSH) by wet grinding method. and grinding time and Ca/Si ratio of the raw materials were considered. XRD (X-ray diffraction), 29Si-NMR (Silicon nuclear magnetic resonance) and TG-DTG (Thermogravimetric analysis) was used to characterize NCSH slurry. Effect of NCSH slurry on hydration, compressive strength and setting time of Portland cement system was discussed, and the dosage of NCSH added was considered as 0%, 1% and 3%. The results showed that the particle size of NCSH reached a minimum value by grinding 2 h and a maximum by 4 h. The particle size also decreased with the increase of Ca/Si ratio, and the amount of NCSH generated is maximum when Ca/Si= 1.0. 3% NCSH (Ca/Si=1.0) shortened the initial setting time (97 min) by 59.9% compared with the blank (242 min), and increased 8 h compressive strength (17.9 MPa) by 203.4%. These results provide a new reference for the preparation of nanoscale calcium silicate hydrate gel seed by wet grinding, and a new early strength agent for cement -based materials was proposed.