Review of Mechanistic-Empirical design approach for asphalt pavements

Mechanistic-Empirical (M-E) design of asphalt pavements is being popularly used in various countries. In M-E design approach, pavement structure is idealized as a layered structure and the critical mechanistic parameters like stress or strain is correlated with the failure criteria. Fatigue and rutting are the two primary and common structural failure modes in asphalt pavements. Traditionally, for fatigue failure the initial critical horizontal tensile strain (ε_t) at the bottom of asphalt layer and for rutting failure the initial critical vertical compressive strain (ε_z) at the top of subgrade layer respectively, are empirically correlated with the fatigue life and rutting life of the pavement section. Accordingly, a safe design solution is obtained iteratively so that the fatigue and rutting life is not less than the estimated traffic repetitions during the design life, usually under standard loading conditions. A lot of work has been done on M-E design approach for asphalt pavements over the 4–5 decades. Hence, this study aimed to do critical and comprehensive review of the M-E design of asphalt pavements. Few research gaps were identified on which the work can be done in future.