Sustainable use of waste in flexible pavement: A review

Around the world flexible pavement is the most favored pavement structure to build road and highways. A massive amount of non-renewable materials and industrial products like aggregates, bitumen, cement, lime, and other additives are consumed during construction and maintenance of this pavement system. Extraction and production of these virgin materials is an unsustainable practice. Wastage of materials, environmental deterioration, depletion of resources, and the spike in material cost led researchers to search for alternative materials that can be used in flexible pavement. This paper provides an overview of such recycled materials that have been successfully used in different layers of flexible pavements. Studies have established that the use of secondary material not only provide an efficient waste disposal technique but also reduce demand for conventional material and reduce overall construction cost. Through this paper, an attempt has also been made to identify the reason because of which, despite having essential studies, their field implementation has been limited and suggest possible remedies by which use of recycled material in the flexible pavement can be promoted.