Abstract:
The growing emphasis on sustainability has highlighted the importance of eco-friendly and cost-effective approaches, particularly in road construction, where the use of renewable, earth-derived materials is encouraged. However, some professionals still believe that using sustainable materials may adversely affect project outcomes in terms of cost and quality. In line with that, this study aims to investigate the impact of incorporating sustainable materials on road construction projects. The study uses a qualitative approach with semi-structured interviews, utilising the Delphi technique with two rounds of expert interviews to gather empirical data, which is then analysed using content analysis. Findings reveal that construction and demolition waste, recycled tyres, waste plastics, fly ash, recycled glass, polyethylene terephthalate plastic bottles, asphalt shingles, cement kiln dust, colliery spoils, recycled asphalt, and warm mix asphalt are the commonly used sustainable materials in road construction. Furthermore, the study identified eleven positive impacts and sixteen negative impacts of using sustainable materials in road construction, which were later classified under each commonly used sustainable material. Overall, this study contributes to advancing knowledge in sustainable road construction, guiding future research and decision-making in the field, and encouraging the use of sustainable materials to promote environmental responsibility.