Effect of Waste Glass Powder and Bamboo Fiber on the Physico-Mechanical Properties and High-Temperature Behavior of a Fly Ash-Based Geopolymer.

This study investigated the properties of fly ash-based geopolymers containing waste glass powder (WGP) and bamboo fiber (BF) after exposure to ambient and high temperatures. Precursor replacement of fly ash by WGP at 2.5, 5, 7.5, and 10% levels coupled with the addition of BF at 1, 1.5, 2, and 2.5% levels was used to enhance the reactivity and toughness of the geopolymer matrix. The impact of WGP and BF on the fluidity, setting time, density, water absorption, and compressive and flexural strengths of the geopolymer pastes was examined. The experimental results showed that the physical properties of the geopolymer were altered by adding WGP and BF. The optimal percentages of WGP replacement and BF addition were 5 and 2%, respectively. Additionally, tests such as thermogravimetric analysis, mass loss, thermal shrinkage, compressive and flexural tests, visual observation, optical microscope, scanning electron microscopy, and X-ray diffraction analysis were conducted to assess the behavior of the geopolymers after exposure to high temperatures (200-800 °C). Addition of WGP and BF led to higher residual strengths, demonstrating that the geopolymer composites tended to gradually densify with increasing temperature due to the pore-filling effects of WGP and the channel effects of BF, while the pure geopolymer continuously developed more cracks and wider pores. The study provides a viable approach for using solid waste materials and renewable resources in the production of high-performance geopolymer composites as sustainable building materials.