الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The current flexible pavement design system in Egypt relies primarily on the 1993 American Association of State Highway and Transportation Officials (AASHTO) Design Guide. It is an empirical design method based on the results of the late 1950’s AASHO Road test.The method has many limitations. One of the serious limitations is the empirical drainage layer coefficients (m2 and m3). These coefficients in addition to the seasonal variation of the roadbed resilient modulus are the only environmental consideration in the method.The Mechanistic-Empirical Pavement Design Guide (MEPDG) was developed to overcome the limitations inherent in the 1993 AASHTO method. Unlike the 1993 AASHTO method, the MEPDG method considers the variation in moisture and temperature throughout the pavement profile on the mechanical properties of the pavement layers. Thus,the main objective of this study was to develop the climatic files to facilitate the implementation of MEPDG in Egypt and study the influence of the Egyptian climate on pavement performance. MEPDG required climatic data which are the hourly air temperature, precipitation, wind speed, percentage sunshine and relative humidity were collected for 16 climatic locations distributed all over Egypt for four years (2009 to 2012). The quality of the data was checked and verified and the data was transformed into the format required by the software. A typical flexible pavement section was simulated using MEPDG at the 16 different climatic locations and the performance predicted using MEPDG version 1.1 was analyzed. The performance indicators predicted by MEPDG are rutting, alligator fatigue cracking, longitudinal cracking, thermal cracking, and International Roughness Index (IRI). Results showed that the pavement performance is significantly affected by the change in the climatic data. As expected, for Egypt, the most significant influence was on the predicted rutting of the asphalt layer. Moreover, the sensitivity study was expanded to evaluate the change in traffic volume, subgrade strength,and ground water table (GWT) level on predicted performance. Results revealed that traffic volume, subgrade strength and depth to GWT have significant impact on predicted MEPDG performance. However, the impact on each predicted distress was different between the investigated parameters. Finally, a comparative study between AASHTO 1993 design method and the MEPDG was carried out. Four cross sections with two different traffic levels and two different types of subgrades located in three Egyptian climatic regions were designed with the AASHTO 1993 design method. These sections were simulated with MEPDG and pavement performance was predicted over the design life and analyzed. Results showed different distress results although all pavements structures were designed with the AASHTO 1993 method. Results showed that although all pavement sections in this study were designed with the AASHTO 1993 method, they exhibited different performance as predicted by MEPDG. The results also showed that pavements located in the very hot to hot climates (Cairo and Aswan) consistently exhibited poorer performance compared to sections located in low-temperature zones such as Alexandria.