Alternative materials for sustainable road construction in Sri Lanka

The current socioeconomic demand requires adequate engineering performance and environmentally friendly materials from the perspective of sustainable development. The scarcity of conventional natural resources and the severe environmental consequences of extraction have prompted research into alternative materials and resources for use in the road industry. Based on the findings of the existing studies, this research aims to explore the suitability of alternative materials for road construction projects towards sustainability in Sri Lanka. A quantitative research strategy was employed in the current study, and the questionnaire was distributed among 44 professionals involved in different types of road projects. The collected data were analysed by using Relative Important Index (RII). 84% of respondents considered alternative sustainable construction materials are highly suitable for the construction of road elements. Bituminous materials, natural soil, crushed rock and cement concrete are mostly commonly traditional materials. Construction and demolition waste (C&D), fly ash, plastic waste, and waste rubber tires were selected as the best materials for base construction, cement kiln dust waste, fly ash, glass waste, and waste rubber for sub-base and C&D waste and glass waste for sub-grade construction. Alternative sustainable materials can solve the waste disposal issue, scarcity of natural materials, and cost savings. Thus, this study presents a collective listing of the most viable alternative materials already in use by the global industry, with the goal of establishing a noble notion for better incorporation of alternative sustainable materials into road construction in Sri Lanka.