15 things we have learned
By Mike Beavin with Mike Anderson, P.E.
Fifteen years ago, in early 2008, the Asphalt Institute (AI) hosted the first of many classes as part of its new National Binder Technician Certification, or NBTC, program.
It was a program that was born out of a desire by the Asphalt Institute members to have a “…consistent nationwide means of ensuring that asphalt binder technicians are knowledgeable and fully qualified to produce valid specification compliance and quality assurance data.”
The key part of that vision was “nationwide” as there had been a certification program operated by the Northeast Transportation Technician Certification Program (NETTCP) for many years prior, but principally in the Northeastern U.S. The Asphalt Institute’s goal was to partner with the NETTCP and Dr. Dave Anderson to create a technician certification program that would be the same throughout the U.S. and Canada where the PG Asphalt Binder Specification was used.
In honor of this fifteenth anniversary, below are fifteen things we have learned in fifteen years of the NBTC program.
Safety first
1. Trichloroethylene cleans up asphalt binder fast
It is also toxic. Over the last fifteen years, we have traveled to many labs for the NBTC and have seen the cleaning solvents that are used. Exposure to many solvents, like trichloroethylene, can pose serious health risks so make sure to check the SDS (Safety Data Sheets) for more information before using. If your lab is still using trichloroethylene anywhere other than under a fume hood while wearing the appropriate PPE (Personal Protective Equipment), we strongly suggest you reconsider the practice. There are plenty of other solvents available that will do the job for you without doing a job on you.
2. Mercury-in-‘the past’ thermometers
Another observation we’ve made during our travels conducting the NBTC program in host facilities is the still-widespread use of mercury-in-glass thermometers. Years ago, due to a variety of reasons including fragility, toxicity and difficulty in maintaining calibration, Asphalt Institute replaced all its liquid-in-glass thermometry with acceptable alternative products. The switch to readily available, versatile nonmercury thermometry drastically reduced the number of devices to maintain and track in our laboratory and eliminated potential mercury spills. Furthermore, in November 2022, the United States Environmental Protection Agency issued a document titled “Phasing Out Mercury Thermometers Used in Industrial and Laboratory Settings.” Their reasoning? Mercury is well-documented as a toxic, environmentally persistent substance, with several states already prohibiting the sale of mercury-containing thermometers. Daniel Gabriel Fahrenheit, your invention in 1714 had a good run, but now we know a fun fact: The Mad Hatter went mad from mercury poisoning.
3. Long hair in the lab may not be a good idea
The standard fluid we use for verifying the calibration of the DSR (Dynamic Shear Rheometer) is very sticky! One unfortunate candidate with long hair discovered that during their practical exam. Loading and trimming was going well but during a close inspection of the trimmed specimen, the student leaned over and some of their hair fell into the standard fluid container. Satisfied with the trimming job, the candidate stood, with their hair pulling the entire jar off the counter and causing it to swing around and bop them on the cheek. Understandably shocked by the pulled hair and close contact of the jar, the technician spun and glared in disbelief. Thankfully, the jar let go of their hair and hit the floor mat. Lesson learned? If you have long flowing hair, you might want to secure its flow while working in the lab.
Prepare to qualify
4. Rocky starts don’t always equal failure
The first few written exam sessions didn’t exactly yield the results we were hoping for from the students. The percentage of students who passed the written exam was worrisome. Was it our instruction? Was it course materials? Were we going to frustrate users and producers by offering a certification that was too rigorous? The actual answer was the reason Asphalt Institute partnered with the NETTCP to take an asphalt binder certification nationwide: In many cases, the published standards were gathering dust. A concise, nationwide interpretation of the published standards was long past due.
5. Beware of old, faded summary notes
If you’ve visited a lab, you’ve probably seen notes taped to the wall or counter near a piece of testing equipment. Likely posted by an informed technician at some point, these useful notes were created to help others by jogging their memory on how to properly perform a test. Now, several years later, that technician may have moved on, but the notes persist, dingy and peeling. Although the notes exist as they are, the standards often change, and there may have been multiple revisions to a standard that didn’t make it to the old testing summary note.
This situation happened early in the life of the NBTC program in which several technicians from the same lab failed to meet the minimum score on their certification exams. Fortunately, their laboratory manager didn’t blame the program. Rather, he decreed all summary notes be removed, not to reappear until new ones were created after a thorough review of the most current standards. Progress.
6. Second chances
Many students don’t necessarily pass the certification exams the first time. In the example cited above the technicians from the same lab went back, studied the standards and discarded the old, grimy (and incorrect) crib notes. On the second attempt, their passing rate jumped higher significantly. Sometimes students need to experience the exams once so that they can prepare better for the next attempt.
7. “Attendance” doesn’t always equal “certification”
As the program grew so did the likelihood of the course materials being reviewed prior to the review course. Word spread that the certification exams were not a rubber stamp program and passing was not a given. Becoming certified was a professional achievement. Reviewing our “MS-25 Asphalt Binder Testing Manual” before arriving improves the chances of that achievement happening.
8. Some excellent technicians struggle with exams
Possibly the most difficult part of administering a certification program is delivering bad news to good people. The 60-question, multiple choice NBTC written exam is open book and note and candidates must complete it in two hours. As with any exam, some individuals struggle from a lack of preparation, but there are some technicians who struggle for other reasons. Maybe English isn’t their first language, or they suffer from testing anxiety. We’ve seen excellent technicians sail through the practical exams and demonstrate an apparent mastery of the tests only to fall short on the written component. We recognize certification may be a way to advance in a career, or in some cases, keep a job so we do everything we can to give each technician the best chance for success.
9. Words matter
As an instructor, it is vital to speak concisely and accurately to maximize the student’s understanding. For instance, while describing the selection of a proper PG binder to use in a certain situation, I unfortunately said that selection was based on the “climactic” temperature. PG binder grade selection is exciting but is better when based on climate than emotion.
Brace for impact
10. “Experience” doesn’t always equal “correct”
There is an old children’s game called “telephone.” It begins with a person whispering a message to the next person around the circle who then repeats it to the next person and so on. By the time the message gets back to the first person, it invariably has changed significantly. It’s funny if you’re playing a game. It isn’t so funny when it happens in a work setting. Imagine a seasoned technician, drawing on years of experience but not the current published standards, who trains a new technician who eventually trains the next in line… You get where we’re going with this. Experience is important but the written word (standards) rules.
11. Old habits can be hard to break
Speaking of old habits…nobody likes to be wrong. Being informed that you may have been doing something incorrectly for a long time has to sting. After the initial hurt passes, most technicians graciously accept the correction and make positive changes to their procedures. Wanting to do things right typically overwhelms wanting to be right.
12. Speaking of thermometers
As noted earlier, the reason for the existence of the NBTC program is to help reduce testing variability nationwide through a concise, standard interpretation of the published standards. When testing asphalt binders, the single biggest source of testing variability comes from some lack of thermal control. After administering and grading hundreds of written exams, one issue has become clear. Nearly 60 percent of all individuals sitting for the 60-question, multiple-choice exam miss the question about temperature offsets. They select the option that applies the offset in the wrong direction, doubling the error. As we know, asphalt binders are highly temperature sensitive, so a very small thermal error can have a very large impact on the accuracy of measured values. An offset applied in the wrong direction doubles the temperature error. Is it possible that nearly 60 percent of binder technicians are making the same mistake at their lab that they made on the test?
13. The published standards were not handed down from the mountaintop
They were written by humans, albeit some pretty smart ones. This fact always leaves room for improvement. Since the NBTC program’s inception, we have had the unique opportunity to see national trends in testing techniques and ‘fixes’ to problematic passages in the standards. We have had the ears of hundreds of people who actually perform acceptance testing, and, as a result, have been able to suggest practical improvements based on their valuable insight.
14. Who’d prefer a smoother assessment?
Other than helping reduce testing variability and the disputes that arise from it, we hear laboratories with NBTC-certified technicians report smoother accreditation assessments. These reports aren’t limited to individual labs; we’ve heard the same message from the assessors themselves.
15. Users and producers make the NBTC truly nationwide
As with many things new, the NBTC program started slowly. The first group to experience the class and exams included the perfect mix of user and producer representative involvement. After that first class, two states out of fifty had technicians representing both users and producers carrying NBTC certification. As of this writing over half of the states have technicians certified from both groups.
Early on, we recognized the importance of the involvement of all technicians responsible for asphalt binder testing and have continued to promote that goal. It can be frustrating for anyone to get failing results on a sample. Even though an uncertified technician can be proficient in their field, if they were the one generating failing results when a certified technician indicated passing results that difference alone could sow a seed of doubt leading to increased frustration for both users and producers. It is far better to minimize that doubt by continued professional development.
BONUS: Will we still be here for the next 15-year milestone?
Achieving certification is important to many professionals, as is the need for users and producers, alike, to produce quality, reproducible test results. So, we fully expect the NBTC program to continue to grow and serve the asphalt industry over the next fifteen years – at which time there may be different authors with new experiences to share in a future article.
Beavin is the Asphalt Institute Technical Training Coordinator. Anderson is the Asphalt Institute Director of Research and Laboratory Services.