The study introduces an innovative approach to utilise ceramic waste aggregates (CWA) in the production of environmentally friendly geopolymer concrete (GPC), as a substitute for conventional coarse aggregates (CCA). This novel method involves the incorporation of class F fly ash (FFA), metakaolin (MK), silica fume (SF) and alkali activators to create the geopolymer concrete. The main purpose of this study is to investigate the mechanical, mineralogical and microstructural properties of FFA, MK and SF in GPC. The results of the investigation reveal a positive synergistic effect among FFA, MK, and SF, leading to enhanced mechanical and microstructural performance of CWA-based GPCs compared to OPC concrete. Among the various mix designs, the F30M50S20 combination exhibits the highest compressive strength (48.5 MPa), flexural strength (6.85 MPa), and split tensile strength (4.14 MPa). Microstructural and mineralogical analyses conducted using SEM, XRD, and TGA techniques illustrate the densification of the matrix and the development of C-S-H gel. Moreover, the formation of mullite mineral is also observed, which could be attributed to the improved performance of GPCs. This study demonstrates the feasibility and advantages of incorporating ceramic waste aggregates into geopolymer concrete.

Keywords: Ceramic waste aggregates, Geopolymer concrete, Mechanical properties, Microstructural analysis, Mineralogical analysis, Sustainable construction.