How Asphalt Labs and Plants Team Up for Stronger Roads

Hot Mix Asphalt (HMA) is the unsung hero of our infrastructure, but getting the mix right is a constant balancing act between the meticulous world of the laboratory and the high-production reality of the asphalt plant. 

We had the incredible opportunity to sit down with one of our favorite people, Tanya Nash, Director of Engineering at Asphalt Testing Solutions and Engineering (ATS). Tanya brought her wealth of experience and unique perspective to a fascinating discussion about the asphalt industry, particularly focusing on the critical relationship between the lab and the plant.

Tanya has spent over 24 years contributing to the industry through her work at the University of Florida, the Florida DOT, and various consulting labs and contractors. Her diverse background, including a license in both Florida and Alabama, offers a truly unique view on materials research and asphalt pavement construction. 

The Lab’s Crucial Role: Guidance, Not Control

The lab's role is not to control the plant but to establish a "perfect scenario" during mix design—a target. The lab then performs the quality control (QC) gut check, pulling a production mix to see how close the plant got to that ideal.

Tanya stressed the necessary translation between the precision of the lab (where things are controlled down to a tenth of a gram) and the reality of the plant (where things are produced in tons). There’s a need for a "window of acceptable" and that expecting the plant to exactly match a tiny lab sample is simply unrealistic. 

When challenges arise and both the lab and the plant point fingers, they often call it a "ghost in the machine" moment, a simple acknowledgment that some variables cannot be perfectly controlled in both places.

Combating Variability: The Top Checklist

When facing mix variability, Tanya suggests starting with a top-three checklist focused on the QA/QC program:

1. Plant-Related: How are materials being handled? Are they checking every incoming load? Are all plant checks and balances being consistently performed?

2. Lab-Related: Are your technicians the best in the world? Because even they can't save you if your equipment is not maintained or calibrated. The lab must always be up-to-date on calibrations and maintain strong relationships with manufacturers.

3. The Solution: The best way to compare your lab process is to "go out and test production mix." You don't know how far off you are until you actually do it.

Technology and Tools: Leaps, Not Ramps

We asked Tanya about the technology helping to bridge the lab-plant partnership. She pointed to tools like PQI gauges, IR bars, and intelligent compaction on the roadway side, all helping to refine and accurately document the placement process.

In the plant, moisture sensors and temperature sensors are crucial, as water is weight and temperatures are a constant battle.

Are there areas still ripe for growth? Tanya is eager to get away from pouring and punching holes into the pavement, hoping for density gauges that are truly reliable without constant recalibration, preventing potential failure points in the pavement.

The Power of Cross-Training and Culture

There’s a controllable factor that leads to success: training. Tanya believes that everyone in the industry wants to achieve that end quality and pride in their work. The tool to create that successful culture is trusting your people by informing them enough to make the right decisions.

Cross-training is key. The plant doesn't need to know how to design a mix, but they need to understand the constraints the mix designers face. Conversely, the designer needs to know the limitations of the plant's belt feeder and slots. When both sides understand each other's language and limitations, communication improves, and they are more willing to work together.

Ultimately, Tanya Nash's experience underscores a fundamental truth: achieving optimal Hot Mix Asphalt quality is less about rigid control and more about informed collaboration. It requires robust QA/QC programs, an embrace of new, reliable technology, and, most importantly, a culture built on mutual understanding and cross-training between the lab and the plant. 

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