Optimisation of bitumen using sulphur as a binder and coconut shell charcoal as a filler for sustainable road construction

Department of Civil Engineering, Vasavi college of engineering, Hyderabad, Telangana, India

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Published online: 3 August 2026

Abstract

An attempt has been made to optimise the bituminous concrete mixes by varying bitumen content and mixing 3% coconut shell charcoal powder as a filler and 1% sulphur as a binder using Marshall Stability Mix Design method. The key properties of the mix such as flow value, density, stability, voids in total mix (VTM), total air voids (AIV), and voids in mineral aggregate (VMA) are determined. The findings of the tests reveal that bituminous mix with 4.5% bitumen has shown better performance in terms of the key properties of the mix. This study further emphasizes sustainable use of materials by replacing the waste products such as Coconut shell charcoal. It is a renewable byproduct of agricultural waste that serves as an effective filler and reduces dependence on conventional, non-renewable fillers. Additionally, sulphur is used as a binder which not only enhances the durability and lifespan of the mix but also contributes to lower environmental emissions. The results of the study can be used in developing a bituminous concrete mix, that has good mechanical properties and eco-friendly composition suiting for high-traffic environments. This approach helps in reducing the carbon footprint promoting circular economy and encouraging waste to wealth concept.