Some Asphalt Plants in Libya; Classification and Performance Evaluation

The production of hot asphalt mixtures used in paving the asphaltic layers of flexible pavement is considered one of the most important stages of the implementation process. Thus production of mixtures that conform to specifications is one of the most important elements in the success of the paving project. Also, any problem that occurs during the processes of preparing materials, mixing them, transporting hot mixtures, and compacting them on the site will necessarily lead to serious damage to the road during service, such as rutting, cracks, disintegration, etc. This paper proposes a scientific procedure for monitoring and evaluating mixing plants. This study included the materials used in the production of hot asphalt mixes and the problems of quality control for asphalt mixes. The study also covered field visits to several asphalt plants in Libya. A series of checks, procedures and precautions were conducted on each quality control item for those plants. The study proposed a method for rehabilitating, evaluating and classifying hot mix asphalt production plants, in addition to the conclusions and recommendations that contribute to avoiding many problems related to the production and implementation of this type of mixture, raising the quality of asphalt concrete production and creating a spirit of competition among asphalt mixture producers. Results show that most of the visited plants were accepted and passed the evaluation method, but to varying degrees. One of them was out of the classification. Finally, proposed guidelines were prepared that include the foundations, methods and standards for qualifying and classifying asphalt plants to ensure that their production complies with the relevant engineering specifications and standards.