multi-layered elastic theory) using initial, undamaged properties of the layer materials. tensile strain at the bottom of the asphalt base) is estimated from a structural model (e.g. Particular attention was paid to traditional analytical pavement design inputs.Īn analytical design approach is divided into two steps: pavement response prediction and pavement performance prediction. Figure 1 shows typical photographs of the project area. This paper focuses on the application of best practice in the design of pavements for a project in the State of Qatar. Additionally, the effects of temperature on lower layers such as cement-bound bases must also be considered because, although their performance is not strictly temperature dependent, the effects of high temperatures can influence constructability, particularly in terms of ensuring proper curing takes place and shrinkage cracking is minimised. High temperatures mean a lower elastic modulus in service, exposure to high levels of ultraviolet light increases the rate of hardening, and asphalt mixtures must also be designed using a binder type and content that will resist defects such as permanent deformation and bleeding. The focus of this paper is on the selection of design parameters for hot climates similar to the Middle East, but the methodology is relevant to any climatic conditions.Īsphalt is one of the most widely used pavement materials and its performance is dependent on both temperature and time (i.e. High temperatures influence the choice of materials, the analysis of those materials in the design process, construction and overall performance during the service life of the pavement. Pavement design in the hottest parts of the world poses a number of challenges for designers. The paper also highlights the best practices associated with the design of pavements with a cement-stabilised base.
The process of developing and selecting design inputs for empirical and analytical design approaches is discussed. This paper discusses how international design practice, knowledge and research of pavement materials were translated into design and, subsequently, construction. There is also a challenge in ensuring that inputs into empirical designs reflect the local environment and the properties of materials used. The predominant challenge is developing realistic predictions of asphalt modulus as an input into analytical pavement design. The environmental conditions experienced in hot climates pose several challenges for engineers when designing a pavement capable of surviving its anticipated service life. This paper discusses the application of best practice and lessons learnt in pavement design for hot climates through the presentation of a case study from a large highway project in the State of Qatar.
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