The State of Qatar is experiencing tremendous growth in infrastructure including road network and highways. The current methods used in design of asphalt pavements in the State of Qatar are empirical and might not be suitable for the design of long-lasting pavements. Given the significant increase in traffic, road authorities in the State of Qatar have been considering the use of mechanistic-empirical methods in the design and analysis of asphalt pavements. This study documents the results of a study in which the mechanistic-empirical pavement design guide (M-E PDG) software was used in the design of asphalt pavements with input parameters that were carefully selected to reresent local materials and climatic conditions. The selection of material properties was based primarily on specifications and design guides in the State of Qatar and on published literature about these materials. The mechanistic-empirical method was also used to assess the benefits of adopting the concepts of perpetual pavement design and also to compare the performance of pavement structures in which various bitumen grades, granular bases and chemically stabilised sub-base were used. A life-cycle cost analysis was carried out to determine the design with the highest net present value among the various options investigated. It is expected that the outcomes of this study would promote the use of mechanistic-empirical methods in the State of Qatar and the region. Inevitably, this will require significant efforts to calibrate material and damage prediction models used in the M-E PDG for more accurate representation of material properties and measured pavements performance.

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Adhesion in asphalt mixtures can be defined as energy required to fracture the adhesive bond between binder and aggregate causing isolation from each other. The main objective of this study was to develop a simple, practical and reliable laboratory adhesion test method enabling direct measurement of the adhesive bond strength of binder-aggregate systems. The adhesion results were subjected to comparative analysis to determine the effect of various variables and parameters. Four binders: two conventional and the other two are their polymer modified varieties, and two types of aggregate, were used to arrive at standardised testing conditions. When the binder thickness increased, the failure transitioned from adhesive to cohesive accompanied by a decrease in the maximum tensile load at failure. Practical work of adhesion decreased with increased testing temperature but the largest decrease was due to moisture conditioning, which increased with increase in loading rate.

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