Predicting Hot-Mix Performance from Measured Properties: Phase II Project Documentation

The problem of providing pavements that perform as designed is a major concern among state transportation agencies. Of importance in addressing this problem is the recognition that performance should drive not only the design process but also the construction process. This approach would necessitate the development of materials and construction specifications that are tied to pavement performance and the development of test equipment and procedures to evaluate the quality of the contractor's work based on predicted performance. In this way, engineers may test and accept as-built pavements on the basis of properties that are used in pavement design and are known to be determinants of pavement life. Project 0-1708, "Predicting Hot-Mix Performance from Measured Properties," was initiated by the Texas Department of Transportation (TxDOT) to develop simple, practical, and reliable test procedures for evaluating the quality of hot-mix asphalt concrete pavements on the basis of predicted performance. To accomplish this objective, TxDOT established a three-phased work plan that called for: 1) conducting a detailed review of recent and ongoing related studies at the state and federal level (Phase I); 2) identifying mixture-, construction-, and structural-related properties that are significant predictors of pavement performance and are under the contractor's control (Phase II); and 3) identifying/modifying existing procedures or developing new procedures that relate the properties identified in Phase II to the expected field performance (Phase III). Phase I of the project was completed. However, Phase II and Phase III were not carried out because the project was discontinued. Thus, this report only documents the pre-construction tests conducted by researchers on a scheduled overlay project along 1-20 in the Atlanta District and the Phase II work plan developed by the researchers, project director, and program coordinator.