Rutting Resistance Potential of High Modulus Asphalt Concrete Pavements

Abstract

The High Modulus Asphalt Concrete Mixture (HMACM) or (EME) (Emobes a Module Eleve) developed in France, since, 1980 by Labatories Central des Ponts et Chaussees CLepC). Due to the increasing in traffic intensity and axle loading this type of mixing were suitable for pavement subjected to heavy duty. Experiments showed that E1.1E mixtures have an excellent moisture damage resistance permanent deformation, fatigue cracking and reducing costs of maintenance and a significant reduction in thickness of pavement. Because of the high stiffness ofE1.1E mixes, the stresses transformed to the bottom laid layer by repeated traffic wheel loads were reduced effectively. This study intend to focus the light into the possibility of producing asphalt mixtures (EME1) and (EME2) that exhibit high degree of high stiffness in order to with stand against the initiation of rutting. The evaluation process will be based on conducting the pnelllllatic repeated load system and the wheel-tracking test. For this pwpose, hard asphalt cement with a penetration grade of 20-30 for E1.1E comparing with conventional asphalt cement with penetration grade of 40-50. The results obtained indicates that increasing the temperature from (25 to 4°C), Resilient Modulus (1..\) reduced by 65 and 20% for conventional and (E1.1E) for base course while at the binder course the resilient modulus reduced by 59 and 16% for conventional and (E1.1E), respectively. "Wheel track test results showed that permanent deformation increased significantly with hard penetration grade bitumen, the rut depth was 2.55 mm while for conventional bitumen was 16.15 mm for base course. While at binder course the rut depth was 2.43 mm while for conventional bitlllllen was 15.1 mm. This increasing in rutting resistance important for reducing and preventing structural failure and in other hand for economy and reducing layer thickness.