Feature Stories

Virtual Asphalt Lab

screenshot of illustrated lab items

Dr. Amit Bhasin designed an open source lab so that students can learn performance grading of road paving materials.

Oct. 9, 2014

There are millions of miles of roads all over the U.S. made of asphalt. To the layperson, every road from Brownsville to Minneapolis looks alike, but they’re not. Each segment is specifically designed for different traffic conditions, heat conditions, and more.

90% of the cost of the road material comes from the cost of bitumen. Bitumen is a by-product of the refinement of crude oil. Originally, it was a leftover waste product, and for that reason, it was easy to get a hold of and also cheap.

But times have changed.  Now, companies charge to provide bitumen, and the bitumen that is obtained by asphalt producers must be further chemically modified in order to be used in roadways.

Associate Professor Amit Bhasin teaches an undergraduate course on materials selection that deals specifically with issues related to binders.

His class focuses on grading these binders, or assigning a value to each sample to predict how it will behave under certain conditions.  Students measure the binder’s viscosity and subject samples to different temperature conditions. The answers they derive allow them to calculate how well a certain binder will perform, based on time, temperature, and age.  For example, they learn how an older, more oxidized binder will perform over time.

Normally, running these tests on bitumen samples requires several machines that cost around a half a million dollars, and it is necessary for students to undergo extensive technical and safety training in order to operate them. To get around some of these associated risks and costs, Bhasin developed a virtual lab in partnership with the Cockrell School of Engineering Faculty Innovation Center.

The virtual lab he helped create is a bit like a computer game.   The user can drag and drop bitumen samples into different machines, which simulate the heating and freezing processes students would employ in a real lab. The outputs, if successful, are saved on the main screen, and the results of each test are displayed for the student (and saved for Bhasin, so that he can look over later).  

screenshot of illustrated dynamic shear rhenometer

The virtual lab has a few additional benefits that set it apart from a physical lab experience. Students can access labs remotely and “do them in their pjs if they want,” says Bhasin.

Students can also make mistakes—a lot of mistakes, which are the kind of missteps that would be both expensive and dangerous in a physical lab. In this environment, when students run tests out of sequence, mix up equipment, or use the wrong tools, the system identifies the error with a small red box and redirects the student to try a different process.

screenshot of action not allowed pop-up over illustration of dynamic shear rhenometer

“The only cost of failing,” Bhasin says, “is that if you do too many processes incorrectly, the system will dump your data as a punishment—and it was designed this way.”

When asked how his students feel about the virtual lab, which was implemented last year, Bhasin says they like the hands on aspect.  “I can stand and wave my hands and describe a test method, or students can watch a technician do it, but this system really allows them to try the processes for themselves, over and over again until they get it right.”