Doctor of Philosophy (PhD)
Department of Engineering Science
Sugarcane bagasse ash (BA), an agricultural byproduct, has been suggested as a sustainable material to partially replace cement and sand in traditional concrete. However, the feasibility of using BA in novel concrete materials, such as engineered cementitious composites (ECC) and fiber-reinforced geopolymer composites (FRGC), has not been investigated. Therefore, the objectives of this study are to: (a) characterize the properties of Louisiana BA produced from different methodologies; (b) quantify the influence of BA as supplementary cementitious material (SCM) on concrete properties; (c) assess the feasibility of developing normal- and high-strength ECCs using BA as SCM and fine aggregate, and (d) determine the viability of employing BA as fine aggregate and as an alternative silica source for alkali silicate solutions in FRGC. The research approach included the production and experimental testing of concrete materials and analysis of the results.
The post-processed BA (PBA), produced by sieving, burning, and grinding Louisiana BA, was identified as the most promising SCM-grade BA. The use of PBA as SCM in concrete and normal-strength ECC decreased workability and compressive strength but improved the durability potential. Moreover, the use of PBA as SCM in normal-strength ECCs produced composites with significantly lower tensile strain capacity than the typical ECC materials ( 2%). In contrast, when PBA and fly ash were used as SCMs (i.e., PBA was used as a replacement to fly ash) in normal- and high-strength ECCs, PBA increased tensile strength, minimally influenced compressive strength but decreased the tensile ductility at high PBA content.
Raw BA (RBA), produced by sieving Louisiana BA, was used as a replacement for silica sand in normal- and high-strength ECCs, and FRGC. For all types of composites, the use of RBA decreased workability and compressive strength yet significantly improved tensile strength and ductility. Moreover, using a ground BA-based alkaline silicate solution to replace silica fume in FRGC produced a decrease in compressive strength but improved the ductility of FRGC. Overall, BA with appropriate dosage can be used for various applications (i.e., as SCM, sand, or silica source for alkali silicate solution) in cementitious and geopolymer composites.
Subedi, Sujata, "A Comprehensive Framework for the Use of Sugarcane Bagasse Ash as Cement and Sand Replacement in Concrete Materials" (2023). LSU Doctoral Dissertations. 6049.
Available for download on Saturday, February 07, 2026