Performance Evaluation of Full-Scale Sections of Asphalt Pavements in the State of Qatar

The population and economy in the State of Qatar have been increasing in the past 5 years. Accordingly, traffic loading has also increased rapidly, which affected the performance of existing roads and highways. This high traffic loading merits consideration of the design and construction of long-lasting pavements that require minimal maintenance. The Transport Research Laboratory (TRL) in collaboration with the Public Works Authority (PWA) of Qatar constructed a field experiment that consisted of six different pavement sections in order to investigate the influence of using different materials and asphalt mixture designs on performance. This paper presents a comprehensive study for the field evaluation of the performance of these trial sections. The evaluation involved the use of the falling weight deflectometer (FWD) and a vehicle equipped with instruments for measuring permanent deformation and cracking. These field measurements were complemented with laboratory measurements on field cores: the dynamic modulus, flow number, and semicircular bending tests. The results revealed that the increase in temperature between winter and summer in Qatar reduced the stiffness of asphalt mixtures by about 80%. The sections in which polymer-modified bitumen was used had the lowest temperature susceptibility. Moreover, the results showed that the bitumen and aggregate type significantly affected the stiffness and the trial sections’ resistance to rutting and fracture.