Microstructural characterization of lime modified bagasse ash blended expansive clays using digital image analysis

Abstract

In the field practice, industrial wastes are recommended for use in construction to achieve both environmental and economic benefits. A novel technique of supplementing lime to the black cotton soil stabilized with bagasse ash is adopted to overcome the shortcomings of the black cotton soil stabilized with bagasse ash alone. The experiments have been conducted by adding lime to the black cotton soil mixed with varied percentages, i.e., 0%, 5%, 10%, 15% and 20% of bagasse ash to ameliorate the properties of black cotton soil stabilized along with bagasse ash. Microstructural characterization such as X-ray diffraction, energy-dispersive X-ray spectroscopy-coupled field emission the scanning electron microscopy (FE-SEM) and Fourier transform infrared (FT-IR) analyses were done to examine the changes caused by the additives. This phenomenon is keenly examined with FE-SEM images by analyzing them using digital imaging technique. The imaging technique carried out using Image J depicts the reduction in void spaces and identified that lime has a perceptible influence in the formation of stable and dense structure of black cotton soil stabilized with bagasse ash rather than stabilizing the black cotton soil with bagasse ash alone. In extension to these studies, new technique in analyzing the shrinkage properties using Python was proposed and the results have been upheld with Image J measurements. After a thorough examination of experimental results, it was revealed that the addition of small amounts of portlandite-rich hydrated lime resulted in a higher reactivity which aided in enhancing the engineering characteristics of black cotton soil over the use of bagasse ash solely for the stabilization.