Behind the scenes in an asphalt mix design lab

By John Davis

labzack_ZACK_webZack McKay
Senior Asphalt Technician
Asphalt Institute

Q: How do you see the Asphalt Institute lab and its commitment to lab quality?

A: We look at accreditation and calibration – those two are the biggest. We keep our equipment up to par in both categories. If you are up-to-date on accreditation and your equipment is properly calibrated, you will have an excellent lab. Employee training is also important.

Q: What innovations are happening in the mix design lab?

A: We’re doing a lot of performance-based testing, such as thermal cracking and fatigue cracking. We’re doing fatigue testing and several procedures for crack testing. We will be recommending the proficiency of certain tests to determine if the data is quantifiable and how well it applies to field performance. “Will the tests tie in with field performance?” is a key question we ask.

Q: What part of your lab work is the most exciting right now?

A: Evaluating all the current cracking tests is definitely exciting. Also doing the performance tests and then evaluating them. Another is testing the various specimens and evaluating the data.

Q: What is your latest and greatest equipment?

A: The Rolling Wheel Beam Compactor is my pick. For making samples and testing, it does the best job. It also does an efficient job of replicating samples. The old piece of equipment did one at a time. The Rolling Wheel does multiples.

Q: How is the lab able to adjust to the cycles of scheduling both research and private testing? For example, how do you fit a week of testing into the wrap-up of a critical six-month research project?

A: We start by scheduling the whole research project, and then build some space and time into the completion dates. We do testing for members and outside customers at various intervals during the span of any given research project. We don’t schedule testing around the research project, but “through” the project or at various times during the research project. For example, we may schedule Day #1 to work on a certain aspect of the research project and schedule Day #2 to do AI member testing. The way the lab is set up, we can do multiple tasks in the same day.

Q: What is one of your primary research projects right now?

A: One is seeing how RAP affects polymer modified asphalt binder. There are others too, such as evaluating tests for intermediate temperature cracking of asphalt pavement.

Q: How do you schedule assignments and assign tasks for various projects? Do you schedule one project at a time? Or multiple projects at a time?

A: We use a utility software called “Basecamp” to manage our projects and maximize efficiency. This way we can keep notes of meetings, assignments and action items all electronically. But we still go back to the white board to plan a rough schedule. We plug in particular events as we plan, such as when the ovens come on, and when we will be compacting samples.

Q: How does the mix design lab function from day-to-day? How do you communicate within the lab? Since you do both testing and research, how do you keep from getting things mixed up?

A: First of all, we make sure we have a plan, a work sheet and a specific agenda that we go by. We use plenty of timers, paper cards for identification and paint pens when we are in sample production. When it comes to fabricating samples, it’s important that we label our mix or compacted specimen, so the next person to handle the sample knows where it came from and where it needs to be. Labeling helps us to tie the sample back to the project, especially when working multiple projects. That’s an example of how we communicate from day to day.

Q: What’s the meaning of having notes on the lab machines?

A: The notes on the ovens are changing constantly, but they tell us exactly what is going on at the time. This is something we recently started doing, as a way to make our sample production more efficient. It helps to manage the production of multiple samples at a time and keeps our oven space organized.

Q: Discuss the importance of being able to adjust to a new way of doing things in the lab?

A: Each of us in the mix design lab is open to doing things in a better way. We help each other adjust. If any of us find a better way to perform a task in the lab, then we’re going to make the adjustment. There’s three ways to look at any task: Does it work well as is? Can we enhance it by doing something different? Do we have a new way of doing it?

Q: It’s been said that your lab has developed a culture where each person has freedom to operate. What do you mean by “freedom to operate”?

A: It’s true. Each lab technician does have the freedom to operate. It’s kind of a millennial mentality. Our manager is able to hand down control to us because he knows that each of us has a high level of competency and trust, which comes from constant training and the application of that training. And we are always providing feedback, both to one another and to our lab manager.

Feedback is important and improves efficiency. The reason I go to ASTM every year is to give a technician’s feedback on the tests. Until the lab tech runs the test, you really don’t know how good it is. The design of the test could look good but have a flaw in the application. Getting a technician’s feedback can be a way to find out if the test works well, needs adjustment or doesn’t work at all.

We try to take ownership in the lab—to make it ours, to be responsible for the presentation of the lab. Each one of us wants to keep “our” lab clean and orderly and complete tests and projects in a timely fashion. Consequently, our work mentality is much better. We are less distracted, more focused on each project and less stressed when under pressure.

Q: Does keeping your equipment up-to-date significantly improve your lab?

A: No question that it does. Keeping our equipment up-to-date is critical for maintaining a high-quality lab. When equipment is up-to-date, you don’t have to apply offsets to make it work. When you have cutting-edge, well-calibrated equipment, you have a lab with high standards.

Q: Talk about the importance of arranging your lab for safety and flow—for both research and testing.

A: We try to make the lab efficient, because if it is efficient – it is safer. We place similar equipment next to one another. A great example of that is our mixing and compacting area. The equipment is close together so there is a minimum of movement from one area to the other. We try to place everything to optimize space and movement. If we have to move things around, we make sure they are mobile and easy to move. Mobility is important in the flow of the lab.

Q: What particular items do you think contribute most to lab organization?

A: An effective yet simple way is using multi-colored pens to label different projects and to label phases within the projects or to label various mixes. We will use one color for Project A, and another one for Project B. Another way is keeping good documentation of notes for each project— especially on paperwork, then filing the paperwork properly.

Work within a specific project will always be labeled with the same color. We use the same color for the same project. When we are testing different samples for different customers, we use a different color for each customer.

Q: How has teaching Asphalt Academy courses helped you improve your lab?

A: The Asphalt Academy trains people, groups and lab technicians. Preparing for the training has helped immeasurably to keep our lab staff current on testing and maintaining our proficiency. Every time we prepare to teach a training course, we have to train ourselves to be knowledgeable about every technical advance and every new change. The preparation keeps us current on everything.

Davis is a contributing editor to Asphalt magazine.