Using Cost, Mix Design, Construction, and Performance Data to Inform Hot Mix Asphalt Pavement Policy and Standards

Abstract

This dissertation integrates and assesses in-service hot mix asphalt pavement data from several typically available but disconnected data sources to inform pavement policy and specification development. This in-service pavement data approach captures connected pavement data from different stages of pavement projects (e.g. mix design, construction, performance after completion) to better understand the relationship between actual in-service performance and mix design, structural design, and construction variables. The dissertation addresses the following research question: what is the value of the in-service pavement data approach in developing hot mix asphalt pavement policy and specifications? To test this question, the dissertation applies this approach using data from 2007 to 2017 to investigate several current Washington State Department of Transportation (WSDOT) research questions. Using the in-service pavement data approach, WSDOT pavement performance questions regarding (1) 3/8-inch versus 1/2-inch nominal maximum aggregate size (NMAS) mixtures, (2) the influence of elevated in-place density mixtures and other mixture characteristics, and (3) high-reclaimed asphalt pavement (RAP) (> 20%) versus up-to-20%-RAP mixtures are analyzed. High level findings include: (1) there is no statistical evidence to suggest a difference in performance between 3/8-inch and 1/2-inch NMAS mixtures; however, the cracking/rutting performance of 3/8-inch NMAS mixtures may be trending higher for older mixtures (ages 9-10); (2) there is no field evidence to suggest an apparent trend between elevated density and increased cracking/rutting performance; however, fine-graded mixture cracking performance may be trending higher than coarse-graded mixtures for older contracts (ages 8-10) and no contracts with a density of 94% or higher perform poorly (≤ 50 cracking/rutting condition value); and (3) there is no statistical evidence to suggest a difference in performance between high-RAP (> 20%) and up-to-20%-RAP mixtures. Ultimately, the in-service pavement data approach is a repeatable framework that can be used to better understand the relationship between actual in-service performance and mix design, structural design, and construction variables. Additionally, it is generalizable to any field with large data sets on in-service pavements (e.g. airfields, highways, etc.). Towards this end, the in-service pavement data approach and high-level findings of the WSDOT case studies may be applicable to the U.S. Air Force pavement program.