Abstract
In the past two decades the State of Qatar has undergone a massive development of its urban centers, with an impressive upgrading and expansion of transportation infrastructures. Such a development, which has been functional for the social and economic growth of the Country, is currently matched by the need of implementing the United Nations sustainable development goals. Thus, greening of the urban structure is being sought by the Public Works Authority (Ashghal) by means of several strategic actions that include the adoption of innovative technological solutions for the construction of road pavements. In particular, ongoing studies carried out under the responsibility of the Quality and Safety Department (QSD) are focusing on the local implementation and validation of recycling techniques. These can contribute to the reduction of natural resources depletion and to the overall mitigation of direct and indirect environmental impacts associated to road construction. This paper provides an illustration of the several recycling opportunities that have been identified for future road pavements in the State of Qatar as part of the so-called “Ashghal Recyling Initiative” and in line with the Qatar National Vision 2030. Materials that have been subjected to experimental analysis and that have shown a significant potential for use include excavation waste, construction and demolition waste, Wadi aggregates, reclaimed asphalt, steel slag and crumb rubber derived from end-of-life tires. However, other recycled materials may also be considered in the future, provided that their chemical, physical and mechanical characteristics are conveniently assessed and that their collection and processing is systematically organized. The overall feasibility of adopting innovative pavement cross-sections containing significant quantities of the abovementioned recycled materials is discussed by considering availability of materials, technical issues related to processing and construction, and predicted field performance. Finally, future prospects of the State of Qatar are also illustrated by referring to the research and implementation needs that will require actions to be taken in the context of a truly sustainable “urban green deal”.
