Abstract:
The increasing demand for sustainable and eco-friendly materials has driven research into natural
resource utilization. This study explores the development of geopolymer mortar incorporating fly ash,
bemban fiber, and natural kaolin minerals. Due to its hydrophilic nature, bemban fiber requires
alkalization treatment to enhance bonding strength within the geopolymer matrix. This research
investigates the effect of 3% NaOH alkalization for 2 hours on the fiber’s properties. The results indicate
that alkalization significantly enhances the physical and mechanical performance of bemban fiber. The
optimal composition of 1.5% bemban fiber with a 70:30 metakaolin-to-fly ash ratio improves key
properties, including water absorption (2.75%), porosity (5.80%), compressive strength (32.58 MPa), and
splitting tensile strength (10.78 MPa). These findings are supported by Fourier Transform Infrared
Spectroscopy (FTIR), which confirms geopolymerization through Si-O-Si asymmetric stretching vibrations
at 974 cm⁻¹. Additionally, X-Ray Diffraction (XRD) analysis identifies a dominant quartz phase, while
Scanning Electron Microscopy (SEM) reveals strong fiber-matrix bonding. This study highlights the
potential of bemban fiber-reinforced geopolymers as a sustainable alternative for cement-based materials,
promoting green construction practices.
