Automate the Asphalt Lab

From sampling to data reporting and every test in between, automating various processes in the asphalt QC/QA chain offers consistency and safety along the way

In and around the asphalt testing lab, there are repetitive tasks that can be relegated to a machine, thus freeing the human technician for other tasks in the quality control/quality assurance (QC/QA) and testing sphere.

Solterra Materials uses InstroTek and Humboldt loading frames to support balanced mix design (BMD) testing for the accurate evaluation of mixes. Both photos courtesy of Solterra Materials

Automated Sampling Example

One of the automated QC/QA procedures that original equipment manufacturers (OEMs) have offered for decades is that of collecting hot-mix asphalt (HMA) samples from the truck bed in a safe and controlled manner. This process could involve a laborer climbing onto scaffolding, plunging a shovel into the back of a truck to get a few scoops of mix that he hopes represent the whole load. He then takes the bucket to the lab to be split and tested, etc. Or this procedure could be made more consistent and safer.

For example, Pavement Technology Inc., Covington, Georgia, includes its remote truck sampling device (RTSD) within its automatic quality control system. This setup, to be erected immediately beyond the loadout area at the plant, sinks a mechanical arm into the fresh load of mix to safely capture a representative sample from the haul vehicle. The arm then retracts and travels along a rail to deposit the mix through a chute to a waiting field ignition oven, where the sample is weighed, burned and re-weighed. A test report produces the asphalt content of the sample. The burned sample is deposited into the field gradation unit, which performs a complete sieve analysis of the sample. All test data is displayed on an excel spread sheet and sent to the asphalt plant’s control house without anyone having to shovel mix, split samples or remove pans from the ignition oven.

Of course, truck sampling devices don’t have to be that complex. In today’s changing environment, QC/QA personnel can select how much automation they desire and how much “hands-on” work they maintain control of from sampling to testing to reporting. Here’s how some of your peers are removing variability and introducing efficiencies in, and around, the lab setting.

Solterra Materials uses InstroTek and Humboldt loading frames to support balanced mix design (BMD) testing for the accurate evaluation of mixes. Both photos courtesy of Solterra Materials

Taking Automation Into the Lab

In a July 9 blog post for Humboldt Manufacturing, Zameer Syed wrote, “Laboratory technicians bring experience and judgement [sic] that no machine can replace. But many of the tasks they carry out every day are repetitive by nature. Handling specimens, recording measurements, moving samples between stations, and repeating the same process over and over again all take time. They also introduce opportunities for small variations between operators. If those repetitive tasks can be carried out automatically and consistently, technicians can spend more time where their expertise really adds value.”

While the technicians use their expertise where it’s needed most, automation can be applied to more mundane and repetitive tasks. Tanya Nash, director of engineering for Asphalt Testing Solutions & Engineering (ATS), Jacksonville, Florida, spoke of how she’s seeing this in action around the country, but specifically in her state.

ATS Laboratory Specialist Tanner Nestle prepares asphalt samples for the oven. Photos courtesy of ATS

“Automation seems to be everywhere from the binder lab, to design, to QC, to mix performance,” she said, sharing that some of the technology is now being evaluated across the country for its impact on how technicians are trained and how expertise is being passed down. She listed these four areas where she sees automation already changing asphalt labs in the Southeast, particularly Florida:

• Binder Lab: “On the production side (suppliers), the idea is turnaround. The use of automated equipment is high—flash point, penetration, specific gravity, and even some viscometers.”
• QC Labs: “The use of automated truck samplers has been approved in Florida and being used by some contractors. The automated binder samplers used at the asphalt plants are in use. Although the automation of different volumetric tests are out there, I am not aware of anyone in Florida using the systems to date.”
• Performance: “The same volumetric automation is used, more for research purposes—universities and proof of concept ideas. Systems are currently being built to look at other performance tests and sample fabrication devices to assist in reducing variability and technician time.”
• Mix Design: “Artificial Intelligence and Machine Learning is in place, and some contractors are using it for their design processes and optimizations in Florida.”

ATS Laboratory Specialist Tanner Nestle prepares asphalt samples for the oven. Photos courtesy of ATS

No matter what part of the country you’re in, Syed noted in his blog, “As testing becomes more demanding, consistency becomes just as important as speed.”

The consistency and speed that Syed wrote of were on the mind of Sathish Banda, P.E., the technical services manager for Solterra Materials, Phoenix, Arizona. “Solterra Materials uses infraTest automatic analyzer to improve the speed, accuracy and consistency of binder extraction testing,” Banda shared. “Automation reduces manual handling, minimizes operator variability and improves safety. This allows laboratory staff to perform other tasks while the analyzer is performing binder extraction.”

ATS Laboratory Specialist Tanner Nestle prepares asphalt samples for the oven. Photos courtesy of ATS

The technicians at ATS also incorporate automation during extractions. Nash shared: “ATS uses automation during their binder extractions—where it is not fully automated, some of the process is. This step is primarily for safety (solvent exposure), productivity, and for repeatability. We don’t have many ‘outside the normal’ automations when dealing with our mixtures. For example, the ignition oven; our ovens all have internal scales with automatic printout systems, which is an automation, just one the industry is so acclimated to. One automation that removes the human error is our DSRs. The programing on the instruments allows little room for error during setup and helps ensure the samples are performed the same every time.”

Banda shared that Solterra Materials also uses InstroTek and Humboldt loading frames to support balanced mix design (BMD) testing for the accurate evaluation of mixes. “Fully automated loading sequences and data collection minimize human error and allow technicians to process more samples and focus on data analysis.”

“ATS is always looking at different automated systems to improve efficiency,” Nash shared. “The key is making sure it is as good as the real thing.”

ATS Asphalt Binder Technician Rebecca Kohl measures the hardness of the asphalt binder during the penetration test. Photo courtesy of ATS

Keep People in the Loop

“Whenever people hear the word ‘automation,’ the assumption is often that it’s about replacing people,” Syed wrote. “I don’t see it that way.”

The people in the lab are integral to its success.

Austin Futrell, P.E., of Prairie Contractors LLC, Opelousas, Louisiana, shared that each of the company’s plants has its own lab with a semi-permanent lab technician. “However, we do have to move around quite often due to night work, multiple projects going on simultaneously, vacations/sickness, or other reasons.” To share files, they use Dropbox. “It connects all of our testing, designing, aggregate properties, and other documents so that each technician has access to every plant. It makes it easy to swap technicians if needed.”

In the Solterra Materials lab, fully automated loading sequences and data collection allow technicians to process more samples and focus on data analysis. Photo courtesy of Solterra Materials

The idea of communication and file sharing is integral to successful automation. This is the cornerstone of the connected work site.

While the Prairie Contractors’ labs don’t use automation “fully,” according to Futrell, they “have a long list of history with our materials that makes it easier for designing and comparing trends.” Futrell has already created multiple spreadsheets for designing and computing results and stated that the highly experienced team is comfortable with the system.

When it comes to that kind of communication and file sharing, whether your team participates in round robin testing out of a central lab you share with multiple contractors or you have a dedicated lab at each of multiple plants, you’ll be sharing data and test results with multiple entities. That data requires reliable transfer.

“Solterra Materials uses R18LabQMS to streamline its asphalt laboratory operations by centralizing quality records, automating calibration and maintenance reminders, and simplifying AASHTO R18 compliance,” Banda shared. “The platform reduces paperwork and keeps teams audit-ready with organized digital documentation. This allows laboratory staff to spend more time ensuring quality and less time managing administrative tasks.”

R18LabQMS isn’t the only system Solterra Materials has in place for digital documentation. The team also uses Stonemont Solutions Software to streamline asphalt QC by managing mix designs, test results and production data in a centralized system. “It provides real-time tracking of quality control results, simplifies reporting and helps to ensure compliance with agency specifications,” Banda shared. “By giving laboratory and production teams quick access to data, Stonemont supports QC personnel to make more informed operational decisions.”

One of the truck sampling devices on the market is the Safe-T Sampler from Stansteel Hotmix Parts & Service, Louisville, Kentucky. This structure is to be erected immediately beyond the silo loadout. When a haul truck pulls alongside the device, an operator stands on the anti-skid tread-plate platform where he has a clear view of the material in the back of the truck, the hydraulic sampling arm, and the receiving splitter chute to the side of the structure, which uses the 180-degree motion capability of the Safe-T Sampler. The operator uses joystick controls to move the hydraulic sampling arm into the material and collects a 20-pound sample. He then uses the joystick to hydraulically move the jaw containing the sample to the splitter chute where the sample can be safely retrieved.

“When the automation is done correctly, the efficiency it can introduce can be high,” Nash said. “It frees up time in which technicians can be performing other tasks or analysis that does not have to be done by manually moving data around. Some of the efficiencies come from product use (our solvent extraction mentioned above), where we do not use as much consumable product as we would with a manual process. Other automation is about the workers’ safety. It prevents downtime from injuries or other issues.”

While sources have stated clear benefits to automating processes for efficiency, quality consciousness or safety, Nash offered a smart caution.

“Automation can be an asset but can also be a crutch,” she shared. “As long as you have the checks and balances in place to verify the automation and what kind of data it is producing, there should be no hesitation to use it. There should always be a basic understanding of the task that is being automated to know when there are issues to be addressed or problems with the system.”

The foundational knowledge she speaks of is one of the many core values humans bring to the table. And one of the many reasons industry professionals from laborers to operators to lab techs to inspectors can rest assured automation is a tool to assist, not to replace, employees in the workforce, making them and their work more consistent and safer.