Comparison of Structural Capacity of Hot Mix Asphalt (HMA) Pavement Designs (AASHTO & TRL RN-31 )

The primary objective of this research is to identify the proper design guidelines in terms of structural capacity, which enables to last longer life span without any major failure. Inducing very high stress on pavement is one of the major reasons for structural failure.

American Association of State Highway and Testing Officials (AASHTO) and the Transport Research Laboratory Road Note 31 (TRL RN-31) are the widely used pavement design guidelines by many road agencies. Hence, this study intends to compare and contrast AASHTO (1994) and TRL RN-31. AASHTO method involve with the complicated empirical equation 3 in appendix which has to be solved by iteration method to obtain the required structural capacity for given conditions. So, computer program was developed using JAVA to solve AASHTO equation. RN-31 and AASHTO methods have been directly compared for a range of subgrade California Bearing Ratio (CBR) and traffic levels.

Model pavements were constructed to evaluate the performance of the pavement for static load and field collected data were used to verify the Finite Element Model (FEM). The verified models were used to evaluate the structural performance of pavements. The main advantage of this review on flexible pavement design guidelines is that the pavement which provide higher structural capacity can be simply identified and constructed, so that, it can reduce the overall cost and provide good platform to the users.