Development of a Correction Method for the Current Pavement ME Methodology in Equivalent Loading Frequency Calculation

Abstract

The AASHTOWare Pavement ME Design uses linear-elastic analysis to simulate the strain responses under axle loadings, and it relies on equivalent loading frequencies to determine the representative elastic modulus of the asphalt concrete (AC) layer. The Pavement ME employs a highly simplified approach for calculating equivalent loading frequency, which often leads to an overestimation of these frequencies, particularly near the AC surface. This paper presents a simple correction method for the current Pavement ME method in loading frequency calculations based on two novel frequency calculation methods. The correction procedure is straightforward, computationally efficient, and readily implementable within the Pavement ME design software. The corrected loading frequencies are validated by calculating critical strains using these frequencies in three representative pavement structures under Michigan's climate conditions. The results indicate that the corrected loading frequency significantly enhanced the accuracy of vertical strain predictions, particularly at the shallow depth of the AC layer.