Design of Perpetual Highway Pavement in Libya Using PerRoad softwaer: Solutions for Maintenance Gaps and Traffic Overload

Abstract

This study aims to identify solutions for the early failure of roads in Libya due to the lack of a pavement management system and an effective load weighing system. The coastal highway in the city of Misrata was taken as a case study, which has high traffic volumes, especially heavy vehicles. The companies involved in the road's reconstruction provided data on average yearly temperatures and the physical properties of the construction materials, This included the modulus of elasticity and Poisson's ratio for both the asphalt mix and the soil used, The design for traffic volumes was based on ESALs reaching 24 M.S.A which is the calculated value for this road. , the ESALS were increased by 5 M.S.A and designed by using  PerRoad program, for perpetual pavement method, and the mechanical experimental method. After the design, both methodologies were compared, and the effect of increasing the number of axles and ESALs on the thickness of the asphalt layers was studied, The results showed that the design of this road using the perpetual pavement method is not affected by the increase in the number of axles and ESALs, which is suitable for achieving a design life of up to 50 years without being affected by the increase in ESALs. The asphalt layers were 25cm thick, while the subgrade layer was 20 cm thick, On the other hand, the mechanical experimental showed a clear impact from the increase in the number of axles and ESALs, as the thickness of the asphalt layer increased from 19 cm to 28 cm, and the thickness of the subgrade layer increased from 30 cm to 40 cm. This design achieves a lifespan of 20 years. The study also indicated that for designs with 15 M.S.A and above, the traditional design is considered over-designed, and the use of permanent pavement is preferred. As for the design of this road, the permanent pavement method was adopted