Participating suppliers of single drum IC rollers. Note that most major manufacturers are developing IC technology. The IC technology from all five of these manufacturers have been involved with ICPF projects in the United States. Also notice that all of the rollers have smooth drums. Historically, the technology is based on smooth drum configurations.
Sakai, Amman/Case, Caterpillar and Bomag padfoot drums with IC technology.
These are suppliers that tell us that they are currently developing IC technology for use on tandem drum asphalt rollers. At this time, Ammann/Case and Dynapac do not have a working roller in the United States, as far as I know.
The IC research to date also includes efforts to identify in situ testing devices and methods that can be used as effective companion tests that can be compared to RMV. One of the challenges that we face is the different depths of influence for IC rollers and for various in situ test devices.
High ks values (dark green) over box culvert near point 12 Point 12 DCP profile shows high CBR values and refusal at about 0.2 m depth because of the culvert Point 13 shows low CBR values below about 350 mm – cannot get good compaction along the edge of the culvert Location of Point 5 – highlighted area – had ponding water which resulted in low stiffness…Moisture Content = 29.5% about 10% wet of optimum
Compaction curves show that there is increasing compaction with pass in CCV, density, CBR, and ELWD
FHWA/TPF Intelligent Compaction and Recent Findings
Key Findings<br />Values of mapping existing support before construction or overlay<br />Significant improvements of rolling patterns, thus, consistent products<br />Improvement of roller operators’ acountability<br />
Key Findings (cont’d)<br />Construction process-control greatly improved<br />IC-MVs correlate to various in-situ point measurements<br />Measurement influence depth varies depending on technology and site conditions<br />Machine operation parameters influence MVs<br />
Lime Stabilized Subgrade<br />Box Culvert<br />Courtesy of Dr. David White<br />
Compaction Curves<br />Cohesive Subgrade<br />Courtesy of Dr. David White<br />
Future Work<br />Improve data management<br />Data management guidelines<br />Standardization of IC data storage<br />Data transfer and archiving<br />Data visualization<br />Correlation with in-situ tests<br />Advanced statistic analyses<br />Harmonize IC roller measurement values (RMVs)<br />
Future Work (cont’d)<br />Implementation Approaches: <br />Use IC RMVs as part of QC/QA<br />Link IC RMVs to mechanistic QA parameters within depths of 1~3 m<br />IC Analysis<br />Link IC data to (long-term) performance<br />Form committee to review/standardize analysis approach/protocols<br />