Characterization of Sugarcane Bagasse Ash as Pozzolan and Influence on Concrete Properties

Abstract

This paper characterizes the sugarcane bagasse ash as a pozzolan and investigates its influence on the hardened properties of concrete. In Pakistan, the sugar industry recycles raw bagasse for power generation, and as a result, tonnes of bagasse ash are produced every year. For this study, the bagasse ash sample was obtained from one of the local sugar mills of Pakistan. The physical, chemical and mineralogical of bagasse ash were investigated by employing X-ray diffraction (XRD), X-ray fluorescence and laser particle size techniques, while the microstructure was studied through scanning electron microscope. In addition, the evaluation of hardened properties like compressive strength, tensile strength, flexural strength and thermal conductivity was also carried out. Here, the concrete mixtures were prepared by replacing the cement with bagasse ash in the ratio of 5 to 30% (by weight). The chemical, physical and mineral results reveal that this local bagasse ash has all pozzolanic properties. The evidence of amorphous and crystalline phases was found in the XRD pattern, along with silicon dioxide (SiO2) which was recorded more than 70% in the ash. It was observed that the workability for bagasse ash-blended concrete mixtures increases with ash content. Furthermore, the bagasse ash mixtures with 10% substitution were found optimal for achieving higher compressive, flexural and tensile strength, while the thermal conductivity showed a consistent drop with higher ash content percentage.