Development of Geopolymer-Based Green Construction Materials for Highway Infrastructure Using High-Content Sugarcane Bagasse Ash

This research investigated the utilization of sugarcane bagasse ash (SBA) for developing geopolymer-based sustainable “green” construction materials that can be utilized in transportation infrastructure. The resulting geopolymer material can be used as concrete in road pavements and as a brick in pedestrian walkways, sidewalks, curbs, and other non-structural elements. The physical, mechanical, and durability properties of the geopolymer-based materials were determined, and mixtures were selected to cast bricks for transportation infrastructure. The microstructure and morphology of the selected mixtures were studied using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results depicted that the compressive strength of SBA–geopolymer bricks depended on various mixture variables, such as SBA dosage, alkali activator ratio, molarity of the sodium hydroxide, and curing temperature and time. The optimum alkali ratio was found to be 1.25. SBA was replaced up to 80% by weight of fly ash. The results revealed that the compressive strength of the SBA–geopolymer composites having 50% SBA and different molar concentrations and curing temperatures were in the range of 11.99–34.91 MPa, which were in accordance with the requirements of ASTM standards. The modulus of rupture was in the range of 3.01–4.44 MPa. The water absorption and strength loss caused by acid attack were also within an acceptable range. SEM, FTIR, and XRD confirmed the formation of geopolymer compounds in different mixtures. The resulting high SBA content geopolymer could be used as a non-structural element in transportation infrastructure.