Trimble has integrated ground-penetrating radar (GPR) technology from specialist firm GSSI with its compaction-control system, allowing accurate density measurement in real time. The unit (roughly the size of a pizza box) fits under the drum and the data can be displayed in the cab of the asphalt compactor, showing the density of the mat.
The reading shown is not just a numerical figure based on estimates of mat stiffness but provides an accurate density reading. According to Kevin Garcia, in charge of civil specialty solutions at Trimble: “It gives you the information from the cab of the machine.” And he added that industry interest is strong. “We already have orders for it.”
Using this system fitted to the machine can deliver accurate readings of the mat density in the top 40mm, or so, layer of asphalt. “That’s all we need to know for our purposes,” Garcia said.
He explained that the system eliminates the risk of both under- or over-compaction, with the former possibly causing early failures and the latter often causing fractured aggregates. This also does away with the need for quality checks using coring in the road after paving, reducing the need for tests alongside live traffic and boosting safety. In addition, this system negates the need for the use of a nuclear gauge to determine density, which requires special training and storage and has limitations on its movement from site to site.
Stand W40420
