DEVELOPMENT OF A ,RATIONAL PROCEDURE FOR PAVEMENT DESIGN

Abstract

This study seeks to obtain an optimal pavement layout by combining theoretical and experimental field approaches to pavement design thereby side-tracking full-scale tests for each new road. To do this, a comprehensive data on traffic census, fundamental properties of road materials such as asphalt, laterites and stabilized laterites were collected from relevant Ministries, Journals, textbooks, laboratory test reports and engineering companies. A computer (FORTRAN) proqramrne was written using BISAR programme equation in conjunction with Srnith-Vvitczak (1981) equation'. The results were used to obtain a mechanistic pavement design with inputs from American Association of State Highway and Transportation Officials (AASHTO) design guide. The: approach produced an optimal pavement layout of 625mm (total thickness) that can exceed its design life with overloaded traffic. It also compares favourably with former procedures for tropical countries. Further research into this "theory-practical" approach is recommended.