Optimizing bio-bitumen mixes through response surface methodology

Abstract

Bio-bitumen, a sustainable alternative to petroleum-based bitumen, is gaining popularity owing to its environmental advantages and potential to address depleting crude oil sources. The purpose of this study is to use Response Surface Methodology (RSM) to optimise bio-bitumen characteristics for sustainable pavements. Bio-bitumen is produced by combining conventional bitumen with biochar, cashew nutshell liquid, waste engine oil, and phthalic anhydride. This study uses RSM to investigate how these components (biochar, cashew nutshell liquid, waste engine oil, and phthalic anhydride) influence important bio-bitumen properties (penetration, ductility, softening point, and elastic recovery). A 2^4 factorial design with 27 trials was employed to optimise the mixing procedure. Statistical analysis, employing visualizations like contour plots and surface plots revealed an optimum bio-bitumen combination having 15% biochar, 1.71% cashew nutshell liquid, 0% waste engine oil, and a phthalic anhydride concentration ranging from 4.54% to 7.5%. This study illustrates the efficacy of RSM in optimising bio-bitumen for sustainable pavements, paving the way for more environmentally friendly road construction.