Development and Impact of the Egyptian Climatic Conditions on Flexible Pavement Performance

Abstract

Pavements are subject to environmental conditions, which affect the performance of both flexible and rigid pavements. The current flexible pavement design system in Egypt relies primarily on the 1993 American Association of State Highway and Transportation Officials (AASHTO) Design Guide. The method has many limitations. One of the serious limitations is the empirical drainage layer coefficients. These coefficients in addition to the seasonal variation of the roadbed resilient modulus are the only environmental consideration in the method. The newly AASHTO released production version of the Mechanistic-Empirical Pavement Design Guide (MEPDG) which is called AASHTOWare Pavement ME Design was developed to overcome the limitations inherent in the AASHTO 1993 method. Unlike the AASHTO 1993 method, Pavement ME Design method considers the variation in moisture and temperature on the mechanical properties of the pavement layers. Thus, the main objective of this study was to develop the climatic data to facilitate the implementation of Pavement ME Design in Egypt and study its influence on the pavement performance. Pavement ME required climatic data which are the hourly air temperature, precipitation, wind speed, sunshine and relative humidity were collected for 16 climatic locations distributed all over Egypt for four years. The quality of the data was checked and verified and the data was transformed to the format required by the software. A typical flexible pavement section was simulated using the ME design at the 16 different climatic locations and the performance predicted using the ME Design was analyzed. The performance indicators predicted by Pavement ME 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.

Flexible Pavements and Climate Change: A Comprehensive Review and Implications

“…They concluded that variabilities in precipitation and, thus, in soil moisture, can reduce road design reliability, although the climate change signal may be minimal in terms of precipitation. Similar studies were also conducted for the USA, Canada, and Egypt [68][69][70][71][72][73].…”

Comparison of AASHTO 1993 and MEPDG considering the Egyptian climatic conditions

“…1. The climatic data for these locations were generated as part of another study by the authors of this paper [12,13]. The weather properties of the three locations are shown in Table 4.…”

Linear structure taxonomy with the account of environmental polystructures impact

“…Various aspects of the impact of environmental polystructures on a linear structure are considered with respect to the stage of its life cycle. For the purpose of control of road structures with the account of environmental factors impact, regulatory documents and design guidelines adopted in different countries provide the use of systematized territorial zoning data [1][2][3][4][5]. Today, development of reliable road structures requires building regional climatic models and using special software to include the optimization techniques in the design process [6][7][8].…”

“…Various approaches exist for solving road climatic zoning issues, they are based on assessment of various conditions, including environmental and climatic, geological and geographical, physico-climatic parameters of the territory [5,9]. Differentiation methods (division of territories) used for transport infrastructure design are developed on the basis of the general theory of physico-geographic zoning with the account of the industry peculiarities.…”