Micro-nanostructures of tobermorite hydrothermal-synthesized from fly ash and municipal solid waste incineration fly ash

Tobermorite has attracted extensive attention as the main hydrothermal product of autoclaved aerated concrete. The optimum hydrothermal synthesis conditions, micro-nanostructure and properties of the solid wastes-based tobermorite were analyzed using XRD, SEM, XRF, TG-DSC, FT-IR, MAS-NMR and nano-indentation. The results indicated that the optimum molar ratio of Ca/Si was 1.0, the mix mass ratio of MSWIFA/(FA + MSWIFA) was up to 62.6%; The incorporation of MSWIFA reduced the degree of polymerization and micromechanical properties of tobermorite, impeded the synthesis of silicon tetrahedron chain and the formation of fibrous tobermorite, and resulted in a low hardness and elastic modulus of tobermorite.