Roller-Integrated Compaction Monitoring for Hot-Mix Asphalt Overlay Construction

Abstract

This paper documents recent experiences using roller-integrated compaction monitoring (RICM) technologies on hot-mix asphalt (HMA) overlay construction projects in Iowa. Recently, new special provisions (SPs) to specifications were implemented by the Iowa Department of Transportation on three projects that required the use of RICM technology for HMA compaction in the breakdown position. The bid costs for implementing the new RICM SPs are discussed in this paper. RICM data were collected and analyzed in conjunction with in situ falling weight deflectometer (FWD), nuclear density gauge, and surface temperature testing conducted on the project sites. Changes in roller compaction control value (CCV), relative compaction, and surface temperature with increasing pass count, and statistical correlations between these measurements are evaluated. RICM pass coverage information was analyzed using univariate and spatial geostatistical methods. Relationships between the FWD modulus and CCV yielded higher correlation coefficients than with relative compaction. Both the CCV and FWD modulus values were significantly influenced by the support conditions underneath the compaction layer, while relative compaction was not. Roller temperature measurements were influenced by the roller travel direction. Analysis of pass coverage information using univariate and geostatistical methods revealed significant differences between different projects. The results, analysis, and experiences documented in this paper provide information to improve future specifications and quality control or assurance guidelines for HMA construction.