Engineering models for the design of long-lasting, sustainable, cost-efficient and climate-responsive pavements for Ashghal road projects in the State of Qatar

Transportation infrastructures are key components of the modern highly interconnected urban built environment, which in the post-oil era may require the adoption of optimized engineering models to be employed for the design of more sustainable solutions. In the specific case of road pavements, these quantitative analyses are essential in order to move away from standard materials and cross-sections, thereby promoting the use of local and recycled materials and of innovative technological solutions, while guaranteeing a long-lasting service life, a sufficiently low life-cycle environmental impact, and an adequate overall long-term economic efficiency. In geographical areas characterized by a hot and arid climate, modelling activities can be quite challenging and for densely populated urban centers they should also include the explicit consideration of the urban heat island effect. In the State of Qatar, all the abovementioned issues are being addressed by the Public Works Authority (Ashghal) through the activities of its Departments and by means of focused collaborations with industrial and academic partners. This paper provides an outline of the pavement-related engineering models that are being employed as part of the studies coordinated by the Quality and Safety Department (QSD) of Ashghal while taking into account local climatic conditions, availability of resources and economic constraints. Considered models span from those based on the physics of pavement structures – for the evaluation of heat transfer and mechanical damage – to those that refer to environmental and economic indicators – typically included in processes for life cycle assessment (LCA) and life cycle cost analysis (LCCA). Results provided in the paper show that the combined use of the illustrated models may be of significant value for the development of future infrastructures in the State of Qatar, provided that they are supported by adequate input data derived from either experimental investigations or sound engineering judgement. Finally, it should be emphasized that although ongoing studies in Qatar are being tailored for local implementation, it is envisioned that they may be fruitfully shared with the international community and that their results may be kept into consideration in other similar scenarios.