Fabrication and characterization of metakaolin-based fiber reinforced fire resistant geopolymer

© 2022 Elsevier B.V.Geopolymers have many advantages over Portland cement, such as low energy cost, reduced greenhouse gas emissions, high compressive strength, high-temperature stability, low thermal conductivity, and high strength at an early age. This study obtained fiber-reinforced geopolymer composite (FRGC) structures using metakaolin (MK) basalt and glass fiber, and the fire-resistant FRGC structure was developed. The morphology, structure, and thermal characterization of fire-resistant FRGC were obtained using SEM, TEM, XRD, XRF, FTIR, and TGA. As a result of SEM, FT-IR, and TGA analyses, it was observed that high-temperature geopolymer samples retained their stable structure. The SEM images also indicated the fiber's effect on preventing surface cracking. Fire-resistant properties were tested by heat exposure in a muffle furnace for thermal behavior of 200, 400, and 800 °C. The mechanical stability of the FRGC blocks was tested using the compression test before and after exposure to high temperatures. In this test, the FRGC block, kept for one hour at 200 °C, still has the compressive strength at the “high strength concrete” class and can be used in skyscrapers (51–76 MPa).