Quantifying results

Sakai’s Compaction Information System (CIS) is an innovative technology that is proving to be a comprehensive compaction measuring tool for contractors.

Intelligent Compaction (IC) is the compaction of soils, aggregate bases
and HMA pavement materials using vibratory rollers equipped with a
digital measurement system and a global positioning system (GPS) for
mapping. This is an emerging technology that could become a new
standard for measuring compaction.

CIS hardware includes a large touch-screen PC display at the operator station, the Compaction Control Value (CCV) sensor and a surface temperature sensor.

Technology advancements like faster computers and improved GPS and software have made IC a reality. The electronic compaction data now available gives new views of the compaction process.

Sakai’s Compaction Information System (CIS) is factory-installed on Sakai’s vibratory single-drum soil rollers or double-drum asphalt rollers and can be used for a variety of applications. CIS uses GPS positioning data and is compatible with most GPS systems currently used on construction projects.

CIS hardware includes a large touch-screen PC display at the operator station, the compaction control value (CCV) sensor and a surface temperature sensor.  AithonMT (machine terminal) software allows the roller to document the compaction process and the AithonPD (plan design) office software creates the plan files and allows for further analysis of the data and for preparing reports that quantify the compaction results.

The compaction sensor is based on Sakai’s experience with compaction measuring systems for vibratory rollers, which dates from the early 1980s with the first compaction meters and the development of the CCV sensor.  For more than 20 years, CCV has been used successfully to improve compaction results on a variety of soils, crushed rock and sub-base materials, and, more recently, with great success for HMA pavements as well. As compaction increases with increased roller passes, the drum accelerations increase according to the machine/ground interaction and the sensor calculates a compaction value, or CCV, indicating the degree of compaction. CCV is a relative value that typically increases with roller passes and can correlate with other conventional single-point density measurement devices as well as mechanistic testing equipment.

The CIS records all compaction data for the entire project simultaneously, including GPS position, CCV, number of roller passes and surface temperature at every pass and at every point along the way. This gives the contractor and engineer 100 per cent coverage of the project, unlike a nuclear gauge.

“The operator can see the results in real time on a big display screen,” says Stan Rakowski, technical services manager for Sakai America. “All recorded information or raw results can be viewed and reviewed immediately on the roller by inspection personnel or the data can be downloaded via USB for further analysis using the office software.”

Machine terminal software allows the roller to document the compaction process while the AithonPD (Plan Design) office software creates the plan files for further analysis of the data.

The PC display is a simple touch screen built into the roller’s control panel. This screen enables the operator to quickly assess the level of compaction required. “The colour display is extremely user-friendly and allows the operator to see where he has been and where he is going to obtain consistent and uniform roller coverage,” says Rakowski. “Knowing when compaction has been achieved eliminates the possibility of over- or under-compacting the material, which will save contractors both time and money,” he says.

“We had a roller operator at one of our demonstrations recognize the change in the asphalt mix during compaction when monitoring the compaction values on the CIS display screen. This was confirmed with the asphalt plant. Sure enough, the plant changed the mix design,” he adds.

“The CCV information is also viewable on the PC screen in real time and is vital information especially when mapping the sub-base,” says Rakowski. “Weak areas can be identified and corrected before the HMA paving begins. This was demonstrated at an IC field demo last year when a portion of the pavement failed under construction traffic.”

The benefits of the technology include reducing paving penalties for the contractor, improvements in quality and savings in compaction costs while at the same time reducing the variability of density.

“This system has proven itself to be very successful throughout our demonstrations with consistent electronic data reports,” says Rakowski.

www.sakaiamerica.com