Long-lasting, durable paved surfaces result from quality compaction

By Jeff Winke

Compaction is the exertion of force on something so that it becomes more dense.

With asphalt paved road construction, compaction is considered one of the most important processes. It is necessary in order to attain high quality and uniformity of pavement materials, which in turn better ensures the long-lasting performance of the paved surface.
Today, “intelligent compaction” (IC) has become a given in discussions of roadway paving. It has become the norm — compaction is pretty much considered intelligent compaction.

IC refers to the compaction of road materials, such as soils, aggregate bases, or asphalt pavement materials, using modern vibratory rollers equipped with an integrated measurement system, an onboard computer reporting system, Global Positioning System (GPS) based mapping, and optional feedback control. IC rollers facilitate real-time compaction monitoring and timely adjustments to the compaction process by integrating measurement, documentation, and control systems. IC rollers also maintain a continuous record of color-coded plots, allowing the user to view plots of the precise location of the roller, the number of roller passes, and material stiffness measurements.

Back in 2011 the FHA reported on a major three-year research project which was designed to verify that IC, which at the time had been considered an “emerging technology,” was mature enough to be implemented in the real world. The intent of the project was to create the blueprint in the FHWA IC strategic plan. This study was under the Transportation Pooled Fund project, which included 12 participating state department of transportation: Georgia, Indiana, Kansas, Maryland, Minnesota, Mississippi, New York, North Dakota, Pennsylvania, Texas, Virginia, Wisconsin.

The report’s Executive Summary states that the project “demonstrated tried-and-true Intelligent Compaction (IC) technologies through sixteen (16) field projects and open house activities, numerous meetings and training for State personnel and local earthwork/paving contractors, and assistance on the development of State IC specifications.”

The IC project’s key conclusions:

• IC mapping of existing support layers is effective in identifying weak support areas for corrective actions prior to the compaction of the upper layers.

• With hot-mix asphalt (HMA) paving, IC tracking compaction roller passes and HMA surface temperatures can provide the necessary means to maintain a consistent rolling pattern within optimal ranges of temperatures for coverage of 100 percent of the construction area.

• IC technologies can be especially beneficial to maintain consistent rolling patterns under lower visibility conditions, such as night paving operations.

• IC technology will have profound influence on the responsibilities of various stages of pavement constructions and will eventually help produce better and more consistent pavement products.

There are intelligent compaction systems available that are designed to track pass counts of multiple rollers or ICs working on the same project. Through secure connectivity each compactor not only performs its tasks, but also becomes part of the overall project. Each operator is not only able to see their own passes, but those made by other machines. This ensures proper compaction from each machine and eliminates redundancy – turning compaction into teamwork.

The IC system is designed to:

• Leverage multiple integrated temperature sensors, so each compactor can achieve consistent results through constant feedback into the system.

• Provide accurate pass counts, geographic locations of each run, as well as georeferenced task assignments and their completion via its GNSS technology.

• Ensure that regulatory IC standards are being met by documenting surface stiffness values through its accelerometer.

• Connect to the Sitelink3D Enterprise service which provides 24/7 access to project data, team collaboration, custom reporting, as well as standard export to Veta management and analysis software, which can provide additional customized information.

Compaction has come a long way from simply rolling over a surface to achieve a stiffer, stronger result.

Jeff Winke is a business and construction writer based in Milwaukee, Wisconsin. He can be reached through jeff_winke@yahoo.com