Evaluation and Harmonization of Intelligent Compaction Systems

Intelligent compaction (IC) is an emerging technology for quality management of compacted pavement layers. Data collected by a vibration sensor and translated to a stiffness-based parameter is usually called the IC measurement value (ICMV). The ICMVs are coordinated with the global positioning system (GPS) data to assess the geospatial distribution of compacted layer properties. The IC rollers can be equipped with the original equipment manufacturer (OEM) systems that are provided by the vendors. However, with the recent introduction of the after-market or retrofit IC kits, it is possible to collect IC data with most regular vibratory rollers. Even though the use of the IC retrofit kits has been gaining popularity, its performance during the field operation has not been documented extensively. In this study, two dynamic vibratory rollers equipped with the OEM IC systems were employed along a test section. A retrofit kit was also installed on one of the rollers to collect the IC data during the same field operation simultaneously with the OEM system. The geospatial distribution of the ICMVs between the two types of systems for the most part was comparable. However, the magnitudes of the ICMVs among rollers and IC systems were somewhat different. These differences in the ICMVs were attributed to the differences in the vibration sensors and their installation as well as the data reduction algorithms among different systems. The reliability of the results from the OEM systems and retrofit kits seemed to be dependent on the proper installation of the vibration sensors as well as the accurate calibration of the GPS unit prior to the field data collection. A validation system and a standard protocol are needed to harmonize the performance of the IC rollers.