A flexible pavement is classified by a pavement structure having a relatively thin asphalt wearing course with layers of granular base and subbase being used to protect the subgrade from being overstressed. In the past, the design of such pavements was based primarily upon empiricism or experience, with theory playing a secondary role in the procedure. However; design and construction of flexible highway pavements has changed significantly during the past three decades.
Since the performance of the AASHTO Road Test, many important concepts have been brought forth. Among these were the demonstration of the major influence of traffic loads and repetitions upon design thickness. Also, the quantitative definition of Pavement failure based on user-oriented rather than only structural failure was a major contribution by that test. That concept led to development of the serviceability performance method. Based on the observed performance of the AASHTO Road Test many thickness design methods have been developed.,
The purpose of this study was to incorporate mechanistic and emperical information in developing a reliable design procedure for highway pavements in Egypt. An engineering technique employing the multilayered elastic concept that has been used in all worldwide recently developed thickness design methods was adopted. · Environ mental and climatic conditions as applicable to the Egyptian highways were introduced. Design charts were developed in an easy way to use by engineers. Comparison between our method and other methods used by some Egyptian agencies are presented. It can be concluded that this pavement design method is reliable, rational and reflecting our own environmental conditions.