Project status
Completed
Start date: 05/15/03
End date: 02/28/04
Researcher(s)
Principal investigators:
- Tom Cackler | 515-294-3230 | tcackler@iastate.edu (project list)
Co-principal investigators:
- Ed Jaselskis | 515-294-0250 | ejaselsk@iastate.edu (project list)
- David White | 515-294-1463 | djwhite@iastate.edu (project list)
Other authors: Vernon R. Schaefer, Isaac Drew, and Lifeng Li
Student researchers:
About the research
This Phase I report describes a preliminary evaluation of a new compaction monitoring system developed by Caterpillar, Inc. (CAT), for use as a quality control and quality assurance (QC/QA) tool during earthwork construction operations. The CAT compaction monitoring system consists of an instrumented roller with sensors to monitor machine power output in response to changes in soilmachine interaction and is fitted with a global positioning system (GPS) to monitor roller location in real time.
Three pilot tests were conducted using CATÂ’s compaction monitoring technology. Two of the sites were located in Peoria, Illinois, at the Caterpillar facilities. The third project was an actual earthwork grading project in West Des Moines, Iowa. Typical construction operations for all tests included the following steps: (1) aerate/till existing soil; (2) moisture condition soil with water truck (if too dry); (3) remix; (4) blade to level surface; and (5) compact soil using the CAT CP-533E roller instrumented with the compaction monitoring sensors and display screen. Test strips varied in loose lift thickness, water content, and length.
The results of the study show that it is possible to evaluate soil compaction with relatively good accuracy using machine energy as an indicator, with the advantage of 100% coverage with results in real time. Additional field trials are necessary, however, to expand the range of correlations to other soil types, different roller configurations, roller speeds, lift thicknesses, and water contents. Further, with increased use of this technology, new QC/QA guidelines will need to be developed with a framework in statistical analysis.
Results from Phase I revealed that the CAT compaction monitoring method has a high level of promise for use as a QC/QA tool but that additional testing is necessary in order to prove its validity under a wide range of field conditions. The Phase II work plan involves establishing a Technical Advisor Committee, developing a better understanding of the algorithms used, performing further testing in a controlled environment, testing on project sites in the Midwest, and developing QC/QA procedures.
Publications
Report: Final Report: Field Evaluation of Compaction Monitoring Technology, Phase 1 (TR-495) (7 mb pdf) September 2004
Related publications:
- TRB 2005 Paper: Real-time compaction monitoring in cohesive soils from machine response (off site), Oct 2011
- Tech Transfer Summary: Soil Compaction Monitoring Technology pdf (Tech transfer summary) Sep 2004
Sponsor(s)/partner(s)
Sponsor(s):
- Caterpillar
- Iowa Department of Transportation
- Iowa Highway Research Board
