Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/489028
W hile intelligent compaction (IC) has been popular in Europe for some time, it's only in the past decade that it began gaining ground in the United States. As with any young technolo- gy, some matters are unresolved. There are no standardized intelligent compaction measure- ment values (ICMVs); OEMs are free to create their own ICMVs to measure the effectiveness of their equipment. And until very recently there was no mathematical way to directly correlate stiffness, which is measured by IC, with density, which is what agencies use to determine compliance with project specs. And while IC can be an important part of quality control, it's not yet mature enough to provide quality assurance. Testing by traditional methods is necessary even when IC is used, but IC data coupled with traditional test results yield a much more comprehensive picture. "A nuclear density test is still required," says Katie Pullen, brand marketing manager for Case Construction Equipment, "but if a company goes strictly off the data from a nuclear density meter, they're not getting load-bearing capabilities. Measur- ing stiffness is said to be a better indicator than density and since primary metrics with IC include rebound detection and stiffness, the combined results will be more accurate and there will be a higher chance of passing if intelligent compaction is used." Even though IC is far from fully evolved, it is a huge leap forward in compaction technol- ogy. Because of this, agencies are including IC requirements in their projects more often and OEMs are expanding their IC offerings. IC offers value right now and no one's waiting for IC to be perfected before applying the current state of technology. Fundamentals Steve DePriest, product specialist, Hyundai Construction Equipment Americas, says the fundamentals of IC are easy to understand. "Depending on the type of system, the infor- mation is displayed temporarily on a digital screen to provide guidance to the operator or, with advanced systems, displayed on the screen as well as stored for future evaluation and analysis." An accelerometer continuously measures the current state of compaction. As the degree of compaction rises the value displayed on the in- strument increases. When the value cannot in- crease any more, the operator knows the maxi- mum degree of compaction has been reached and the compaction process can be stopped. "If no stable value is established, an analysis of the roadbed is required," says DePriest. If compaction continues after the measurement stabilizes, over-compaction can occur. This can cause the vibratory machine to jump, which may result in damage to the compactor. The Volkel Mikroelektronic IC systems of- fered by Hyundai can be installed at the fac- tory or in the field. Current compaction equip- ment models can be upfitted with the system at any time. Hamm Compaction Quality (HCQ) pre-wire kits are available for all H i-series soil and HD+ and HD+ i-series asphalt rollers. Kits include accelerometers, temperature sensors, a mount for the GNSS receiver, and a mount for a tablet PC. This allows the GNSS receiver and tablet computer of the HCQ system to be moved among machines, even from soil to asphalt and pneumatic tire compactors. All relevant dimensional data, such as size and type of roller and offset of the receiver to the center of the drum, are shared with the system by the machine's computer. This ensures consistently EquipmentWorld.com | April 2015 39 Hyundai Hyundai offers IC systems from Volkel Mikroelektronik on its single drum models of 7 tons and greater, including the HR70, HR110, HR120 (shown), and HR140C-9. The systems can be installed at the factory or in the field and may be added to a machine at any time.