Green alternative to asphalt paves way to provincial honour for former Lethbridge College students
07, Jun, 2021
EDMONTON, June 7, 2021 – Few of us enjoy the eyesore of old rubber tires in landfills or on the side of the road. But, it’s good news for the environment and our visual aesthetic that a former team of Lethbridge College students has found a way to literally get more miles out of them - by turning them into asphalt.
This innovation by the former team of civil engineering technology students gained traction at the provincial level, paving the way to recognition as a finalist for the Association of Science and Engineering Technology Professionals of Alberta’s (ASET) Capstone Project of the Year Award.
Amy Gregorchuk, Liudmyla Wagner and Daniel Mitchell, now graduates of Lethbridge College, capped off their end-of-term program last year with a project that explored a concrete solution for repurposing rubber to meet the road by essentially becoming the road.
What got the wheels spinning for them to pursue this particular project was an observation that concerns about recycling and landfills were on the rise. Their goal was to keep tires out of garbage dumps while also improving the qualities of hot mix asphalt.
“Our original idea sparked from wanting to recycle materials, such as using glass or rubber in asphalt. Glass has been trialled much more than rubber, and we were very interested in how rubber would fare and what effects it would have,” said Gregorchuk.
Their Capstone project was the first in Lethbridge College’s history to examine the effects of crumb rubber in hot mix asphalt. Gregorchuk says that, while there have been a couple of studies and test areas in Alberta, it doesn’t appear that hot mix asphalt designers have yet determined how to adapt mixtures to the province’s climatic conditions.
The former team sought to learn how asphalt designs were affected by the inclusion of rubber. Would it work as well, if not better, than conventional asphalt? Would it be a realistic option for more Canadian companies and roadways? Would the rubber mixture have a higher life expectancy?
They performed a series of tests using crumb rubber, which is made from 100 per cent clean, recycled rubber that provides safe, resilient and non-abrasive infill. Crumb rubber is created by removing the steel belts from tires and converting the rubber into small particles.
They used two different crumb rubbers in an attempt to adjust the characteristics of the asphalt mix briquettes - small blocks of compressed asphalt cement. Their process focused on mix design proportions with varying sizes of crumb rubber and percentages of asphalt cement added to the test samples. Through this experimentation phase, they were able to observe how the strength and qualities of the asphalt were affected.
In order to determine if crumb rubber was useable in hot mix asphalt, it was tested in accordance with American Society for Testing and Materials (ASTM) standards. Once the data was collected, comparisons were conducted to conclude that recycled crumb rubber would be an applicable ingredient in hot mix asphalt.
Due to the project’s limited time scope coupled with COVID-19 restrictions, the former team was unable to perfect an asphalt mix that was immediately viable, but acquired enough information to know how to make it market-ready.
“Our biggest challenge was creating a mix design that had the correct portions of each component of the hot mix asphalt,” added Gregorchuk. “We are confident that, with additional testing and tweaking, this hot mix could be a popular option in the near future.”
“This former Lethbridge College team put the pedal to the metal and, working within the strict confines of their end-of-term project timeline, made important progress in exploring the potential use of environmentally friendly materials in the construction of roads and highways,” said ASET CEO Barry Cavanaugh. “Kudos to them for driving forward an idea that could have positive ramifications for the environment and the future of Alberta as a whole.”
In addition to handing out the Capstone Project of the Year Award to deserving engineering technology students, the ASET Education and Scholarship Foundation provides scholarships, bursaries and educational funding to enhance and support the education of students pursuing engineering technology studies.
ASET is the professional self-regulatory organization for engineering technologists and technicians in Alberta. ASET currently represents over 16,000 members, including full-time technology students, recent graduates and fully certified members in 21 disciplines and more than 120 occupations across a multitude of industries.
Michele Penz, Calico Communications for ASET