CAS (CaO–Al₂O₃–SiO₂) glass-ceramic was prepared from class C fly ash (FA) and the powdered waste glass (PWG) in the weight ratio of FA: PWG = 40: 60 (denoted as F40) and sintered in a single-stage at 700-1,000 ^oC. X-ray diffraction (XRD) analysis showed that the crystallization of the mixture into wollastonite, augite, and zeolite had occurred after sintering. Microscopically investigation showed acicular type crystals distributing on the glassy matrix of the F40, in correspondence to the XRD result. The F40 showed promising Vickers hardness and flexural strength with the maximum values of 7.4 GPa and 57.6 MPa respectively. Further attempt to improve the mechanical property of the obtained glass-ceramics using the two-stage sintering profiles was achieved with the respective maximum hardness and flexural strength of 8.2 GPa and 62.5 MPa. The result showed that the prepared CAS glass-ceramics were suitable for use as low water absorption tiles according to the Thai Industrial Standard for Ceramic Tiles (TIS 2508-2555). The superior physical and mechanical properties as well as the low firing temperature opened the opportunity for waste management by up-cycling as a new building material

Keywords: Glass-ceramic, Fly ash, Glass cullet, Flexural strength, Vickers hardness