Understanding the True Economics of Using Polymer Modified Asphalt Through Life Cycle Cost Analysis

Abstract

This article reports on a study that analyzed an extensive collection of field performance data, making direct comparisons between polymer modified asphalt (PMA) mixes and unmodified conventional mixes. The data included 84 pairs of PMA and unmodified companion test sections from the Federal Highway Administration (FHWA) Long Term Pavement Performance (LTPP) program and other test sections across the U.S. and Canada. This article uses life cycle cost analysis (LCAA) to evaluate the overall long-term economic efficiency between competing alternative PMA strategies provided in the original study. The three example scenarios are: using conventional unmodified mixes for all layers, using PMS for the top 2-inch wearing surface only, and using PMA for both the wearing surface and bottom 4-inch base layer. The results showed that while PMA increased initial construction cost by 1 percent per inch of PMA used, the overall life cycle cost savings over 40 years was substantial (15.5%). Even in more conservative scenarios where more PMA was used, the life cycle cost savings were 4.5% to 14%.