Hamm Debuts Real-time Asphalt Density Sensor for HD+ Rollers

During this year’s World of Asphalt in St. Louis, Hamm showed off its brand new Smart Compact Pro real-time density technology for its HD+ series of tandem rollers.

The system adds a real-time density scan sensor beneath the center of the roller that determines the asphalt density by measuring the dielectric conductivity, which forms the basis for correlation with density or porosity.

Tim Kowalski, applications support manager for Wirtgen America, says this ground-penetrating radar will be controlling the machine versus the previous compaction software that used several sensors.

“We can eliminate the accelerometer, and we can eliminate the temperature sensors, because there's a built-in temperature sensor on the [radar] unit,” he says. “And we can eliminate the weather station. Now the machine, instead of being controlled by these sensors, is controlled by the actual density reading.”

Equipment WorldThis new radar sensor was preceded by Hamm’s Smart Compact assistant, which automatically controls compaction modes and forces for both drums and has been available since 2022.

According to Hamm, by adding Smart compact Pro, which launches in August, contractors can see time and cost savings as it allows  less experienced operators to achieve stronger compaction results.

Calibration involves taking three measurements in different areas.

“We pick three different locations,” Kowalski says. “We'll set a nuke gauge down, get a reading. We'll bring the machine over, get another reading. And we'll put input from the nuclear gauge, or any gauge, into the machine. We do that three times. Now, the machine is correlated to the gauge that we're using to read density.”

He notes that even if operators turn off the Smart Compact Pro’s ability to the run the process automatically, the sensor will still collect density data. And in November, he says, Hamm will connect this information to its Track Assist intelligent compaction system app.

Equipment World“Now not only are we just going to read it individually from the machine, we are going to record it in a pass count,” Kowalski says. “So now we have pass count. We have stiffness. We have temperature, and now we have density that we're going to be able to record.”

Kowalski adds that Smart Compact Pro offers a solution for contractors in states that are looking to eliminate coring, and some departments of transportation have already tested this system with carts for final density.

“If we can eliminate using cores and eliminate our traffic control, it's a huge safety standpoint, as far as not having people out there after the job is done,” he says. “So, it's a huge savings to the contractor. You're going to have a much more consistent, compacted material.”