Future Design of Perpetual Pavements for New Mexico

This study provides guidance for future designs of perpetual pavements in New Mexico. The perpetual pavement in this study refers to only hot mix asphalt (HMA) pavement sections designed for a useful life of 50 years or more without having major distresses such as fatigue and rutting. This project conducts an in-depth literature search of state departments of transportation and foreign agencies pertaining to design and application of perpetual pavements. This report highlights the perpetual pavements designed by state highway agencies nationwide and summarizes their experience, as well as their conclusions on perpetual pavement performance. The Mechanistic Empirical Pavement Design Guide (MEPDG) is used as an analysis tool. This study evaluates the effects of moisture infiltration on perpetual pavements. A full literature review conducted on moisture damage testing indicates that dynamic modulus testing of wet and dry HMA samples is found to be an appropriate approach to account for moisture damage in perpetual pavements. This study determines the combination of layer, stiffness, and thickness to produce optimal perpetual pavements. This is achieved by creating a test matrix of varying MEPDG input parameters. Input parameters such as HMA layer thickness, HMA mix design, and performance grade (PG) binders are varied and analyzed using the MEPDG. From the trial designs, perpetual pavements have been found for moderate to high truck traffic using HMA thicknesses varying from 10 to 15 inches. Perpetual pavements have been found both with and without rich binder layers (RBLs). Results shown in this study indicate that fatigue cracking is not a major concern for designing perpetual pavements in New Mexico’s conditions (using MEPDG), rather rutting is more of a concern.