Intelligent compaction (IC) is a roller-based innovative technology that provides real-time compaction monitoring and control. IC can monitor roller passes, vibration frequencies/amplitudes, and stiffness-related values of compacted materials or intelligent compaction measurement Values (ICMV). Various ICMVs have been introduced since 1978. Based on the five levels of ICMV in the 2017 FHWA IC Road Map, the current implementation of ICMV in the United States has been limited to Levels 1 and 2. However, Level 1 and 2 ICMVs fail to meet the FHWA IC Road Map criteria. To achieve the full potential of IC technology, Level 3 and above ICMVs are needed to gain the confidence of agencies and industry and the adoption of IC to soil and base compaction. This project aims to (1) evaluate Level 3-4 ICMV systems against Level 1 ICMV systems for soils, subbase, and base compaction and (2) develop a blueprint for future certification procedures of IC as an acceptance tool. This study also aligns with the goals of the ongoing HWA IC for foundation study and the TPF-5(478) pooled fund study. This final report details the ICMV background, field test efforts, analysis results, and an IC specification framework for compaction acceptance.

TRB's National Cooperative Highway Research Program (NCHRP) Report 676: Intelligent Soil Compaction Systems explores intelligent compaction, a new method of achieving and documenting compaction requirements. Intelligent compaction uses continuous compaction-roller vibration monitoring to assess mechanistic soil properties, continuous modification/adaptation of roller vibration amplitude and frequency to ensure optimum compaction, and full-time monitoring by an integrated global positioning system to provide a complete GPS-based record of the compacted area--

This report describes a study of intelligent compaction (IC) technologies, within the context of actual construction projects, for its potential as a component of INDOT's QC/QA for soils. The output from an IC-equipped roller compaction equipment is a real-time area mapping of the compacted lift stiffness as captured by the IC measure. Data was collected to evaluate the correlation between each of two IC measures-compaction meter value (CMV) and machine drive power (MDP)-and in situ embankment quality test measures, the chief in situ test being the dynamic cone penetrometer (DCP) test which INDOT uses for soil embankment acceptance testing. Researchers sought to understand how well the IC measures might assess embankment quality as currently evaluated by the in situ measures. Window-averaged IC measures were compared with the in situ DCP test points. For CMV, a variable correlation was found between the average CMV and DCP values from 74 in situ locations. Also, a limited head-to-head comparison of CMV and MDP with the in situ measures provided some indication that MDP should be studied further. Lessons were learned regarding the elimination of bias in future correlation studies, critical provisions to facilitate best data quality, and important aspects of data management. IC technology holds promise for monitoring the consistency of the soil compaction effort and flagging weak areas in real time during compaction operations. However, further insight is needed regarding the correlation of the DCP measure with both types of IC measures for various soil characterizations and field moisture conditions.

While having been successfully used for soil compaction for many years, intelligent compaction (IC) technology is still relatively new for asphalt pavement construction. The potential of using intelligent compaction meter value (ICMV) for evaluating the compaction of asphalt pavements has been hindered by the fact that ICMV can be affected by many factors, which include not only roller operation parameters, but also the temperature of asphalt layer and the underlying support. Therefore, further research is necessary to improve the application of IC for the asphalt compaction. In this study, the feasibility of IC for asphalt compaction was evaluated from many aspects. Based on that, a laboratory IC technology for evaluating asphalt mixture compaction in the laboratory was also developed. In this study, one field project for soil compaction was constructed using IC technology, and a strong and stable linear relationship between ICMV and deflection could be identified when the water content of soil was consistent. After that, more field projects for asphalt compaction were constructed using the IC asphalt roller. The density of asphalt, as the most critical parameter for asphalt layers, along with other parameters, were measured and correlated with the ICMVs. Various factors such as asphalt temperature and the underlying support were considered in this study to improve the correlation between the density and ICMV. Based upon the results of correlation analyses, three IC parameters were recommended for evaluating the compaction quality of resurfacing project. In addition, the geostatistical analyses were performed to evaluate the spatial uniformity of compaction, and the cost-benefit analysis was included to demonstrate the economic benefits of IC technology. Based on the test results of field projects, the IC indices were further utilized to quantify the lab vibratory compaction for paving materials. The compaction processes in the laboratory was monitored by accelerometers. Using Discrete-Time Fourier Transform, the recorded data during compaction were analyzed to evaluate the compactability of paving materials and to further correlate to the field compaction.

Mechanistic pavement design procedures based on elastic layer theory require characterization of pavement layer materials including subgrade soil. This paper discusses the subgrade stiffness measurements obtained from a new compaction roller for compaction control on highway embankment projects in Kansas. Three test sections were compacted using a single, smooth steel drum intelligent compaction (IC) roller that compacts and simultaneously, measures stiffness values of the compacted soil. Traditional compaction control measurements such as, density, in-situ moisture content, stiffness measurements using a soil stiffness gage, surface deflection tests using the light falling weight deflectometer (LFWD) and falling weight deflectometer (FWD), and penetration tests using a dynamic cone penetrometer (DCP), were also done. The results show that the IC roller was able to identify the locations of lower soil stiffness in the spatial direction. Thus, an IC roller can be used in proof rolling. IC roller stiffness showed sensitivity to the field moisture content indicating that moisture control during compaction is critical. No universal correlation was observed among the IC roller stiffness, soil gage stiffness, back-calculated subgrade moduli from the LFWD and FWD deflection data, and the California bearing ratio obtained from DCP tests. The discrepancy seems to arise from the fact that different pieces of equipment were capturing response from different volumes of soil on the same test section.