Development of Geopolymer-Based Construction Materials Using High-Content Sugarcane Bagasse Ash

Abstract: This research investigated the utilization of sugarcane bagasse ash (SBA) for developing geopolymer-based sustainable “green” construction materials that can be utilized as a brick in construction industry. These bricks can be used in load-bearing and non-load bearing walls, in pedestrians’ 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 which meets the ASTM requirements. 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 like 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 to 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 due to acid attack were also within acceptable range. SEM, FTIR, and XRD confirmed the formation of geopolymer compounds in different mixtures. The resulting high SBA content geopolymer had mechanical and physical characteristics in acceptable range, so these can be used as a structural element in the construction industry.