Former Lethbridge College team’s concrete project honoured as finalist for provincial award
26, Oct, 2021
EDMONTON, Oct. 26, 2021 – A former team of Lethbridge College civil engineering technology students has received a provincial honor for investigating whether or not the addition of polypropylene fibers to concrete can help protect it from conditions that would otherwise cause it to crack or deteriorate.
The former team of Lane Roggensack, Robert Beerda and Brett Porter was recently recognized as a finalist for the Association of Science and Engineering Technology Professionals of Alberta’s (ASET) prestigious Capstone Project of the Year Award.
In construction, rebar is often added to concrete to increase tensile strength. However, it cannot add strength to the exposed edges of concrete. As a result, cracks can form along those edges, allowing water to infiltrate the concrete and corrode the rebar reinforcement.
For their end-of-term Capstone Project, the former Lethbridge College team experimented with adding polypropylene fibers to concrete without rebar reinforcement. Synthetic fibers have been in use in modern construction since the 1960s but the former team believed that they are not currently utilized to their fullest potential. Research they’d seen had indicated that fibers such as polypropylene have more benefits than rebar in some situations, including crack resistance, post-crack toughness, and impact resistance.
The former team created cylinder and beam samples to compare the compressive and tensile strength of concrete containing polypropylene fibers to concrete reinforced with rebar. The cylinders with polypropylene fibers fared better than the beams in that the cracks that formed within them were smaller and less invasive, enabling the cylinders to remain intact. The beams with fibers split in half - an outcome that wasn’t expected. The concrete beam samples with rebar ultimately proved to be significantly stronger than the concrete beam samples containing fiber.
They also discovered that the addition of fiber made the workability of concrete lower than regular concrete. Concrete slump with fiber was 16-times lower than normal slump. A slump test measures the consistency of fresh concrete before it sets, and is used to ensure uniformity for different loads of concrete under various conditions. It can serve as an indicator of an improperly mixed batch.
In the end, the former team determined that polypropylene fibers alone are not enough to increase the tensile strength of concrete and, therefore, are not a viable replacement for rebar.
“However, we believe that adding a low percentage of fibers to concrete to work in tandem with rebar may have a positive effect,” said Roggensack. “This is a project we would love to research if we had time and resources to do so.”
“This Capstone Project is literally a concrete example of future engineering technologists thinking outside the box and looking for new ways to approach well-established construction practices,” said ASET CEO Barry Cavanaugh.
The former Lethbridge College team’s project is one of seven finalists named by ASET for the Capstone Project of the Year Award. The winning project will be announced later this year.
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