"Sometimes operators stay on the material longer than necessary and give it another pass or two, just to be sure," says [Dave Dennison]. "Experience may tell them they need a certain number of passes. But onboard compaction monitoring systems may indicate they've achieved a target stiffness in fewer passes. If you're saving passes, you're saving time, fuel and wear and tear on the roller, which are all positive things."
PAVING INNOVATIONS PRODUCTIVITY plus QUALITY CONTROL Available technology helps smooth the path to compaction specs By Kim Berndtson T echnology designed to help tion monitoring. As early as the typically will get a higher degree of you achieve your soil and 1980s, Europeans were using these rebound and a higher reading,” notes asphalt compaction objec- systems to help determine the effec- Dave Dennison, BOMAG Americas. tives has made tremendous tiveness of the compaction process. This information can be used by headway in recent years, Similar systems began appearing in an intelligent compaction roller — a and is continuing to evolve at a rela- the U.S. earlier this decade. roller equipped with a documenta- tively rapid pace. Its ultimate goal is At the heart of onboard compac- tion and feedback system — to auto- to quantify density on the run — i.e., tion monitors is an accelerometer that matically adjust parameters such as identify density in real time under measures the response or rebound of vibration direction. The roller opera- the roller. the drum in respect to the frame. tor can also use the stiffness data to While the technology isn’t quite This measurement allows a stiff- determine at what point to conduct there yet, there are several options ness value to be displayed and cor- traditional sonic and nuclear density currently available that can help you related to density. (It’s important to tests and spot core tests. quickly and effectively reach target note that stiffness is not the same as “Currently this new technology densities. density.) needs to be used in conjunction with For example, loose, lightly com- existing density tests,” says Denni- Monitoring soil stiffness pacted soil or asphalt will have a son. “We’re not at a point where it Soil compaction has essentially smaller response or rebound. “As can replace those tests. It’s another led the way with onboard compac- you make successive passes, you quality control tool contractors can 30 asphalt contractor • www.asphalt.com • February 2010 PAVING INNOVATIONS GPS mapping technology, such Mapping a clearer picture as Caterpillar’s AccuGrade ing technologies and grade con- Compaction GPS Mapping GPS mapping systems are also trol systems, including the analysis and Monitoring System, lets becoming more accepted on compac-
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