A Study on Intelligent Compaction and In-Place Asphalt Density

Abstract

Intelligent Compaction (IC) technology is an innovation of roller technology that can be used to improve quality control (QC) of the asphalt pavement compaction process. It is increasingly used by the asphalt paving industry in the U.S. Currently, IC is being adopted by many federal and state highway agencies. Asphalt IC technology uses accelerometer-based methods to collect IC measurement values (ICMV) that relate to the stiffness of the compacted materials. Across the U.S., in-place asphalt density measurement is still the de facto method for acceptance as the in-place densities relate to long-term performance of asphalt pavements. Past limited research has not been successful in finding a strong correlation between ICMV and measured in-place density. To accelerate the implementation of IC technology, it is essential to further study the relationship between IC measured data and core density to assess the use of IC measurements beyond QC. This project includes extensive field studies and data analysis and modeling in order to investigate the relationship between ICMV and other IC measurements (such as pass counts, temperatures, vibration frequencies/amplitudes, direction, speed, etc.) and asphalt in-place densities. The pass-by-pass ICMV correlate well with nuclear density gauge measurements during breakdown compaction. As the final ICMV does not correlate well with core densities, the final ICMV data is not recommended to replace cores for acceptance. An IC-based nonlinear panel data model was also developed to reasonably predict asphalt in-place density as an enhanced QC tool. Recommendation are also provided regarding future research and implementation to maximize the potential benefits of IC.