Future Innovator / Sigl becomes quick learner in concrete lab

Keegan Sigl is living testimony that saying yes and walking through doors of opportunity can lead to a whole new world of education.

That’s one of many lessons the senior civil engineering major has learned at South Dakota State University this semester. Since late January he has been part of the Future Innovators of America program at the Lohr College of Engineering.

This is the fourth year for Future Innovators of America Fellowships. Recipients are awarded $5,000 with $4,500 as a stipend and $500 to cover the cost of lab supplies or travel to disseminate the results of their projects.  

The fellowships were created to provide unique research opportunities for undergraduate students in the college. Any student is eligible to apply as long as they are attending full time and have a GPA of 3.0 or higher. Each student works with a potential project mentor, who must be a faculty or research staff member, to develop and submit a research plan that entails learning by doing. 

This year’s class of eight Future Innovators was announced in late November, and Sigl wasn’t on the list. The program wasn’t even on his radar.

Joins project in late January

Another student was planning to work with assistant professor Akram Jawdhari on “Carbon-Fiber Reinforced Polymer Rod Panels.” However, when spring semester began, the student had a change in plans. Jawdhari, an expert in emerging concrete technologies, had already received funding from the American Concrete Institute for the project.

Jawdhari sent an email to the students who had taken his senior-level concrete theory and design class asking if anyone wanted to be part of the project. 

Sigl, a 2022 Lincoln High School graduate, stepped forward. “I’ve always been interested in structural work. I saw this opportunity as a way to get involved in research and gain in-depth knowledge.”

While Sigl carries a 3.982 GPA and did well in Jawdhari’s class, he freely admits to being a novice when it comes to research work and technicalities of concrete products. “I was totally lost when first came to (Lohr Structures) lab. But I got lectures on the technology and did self-research. It’s a thing where you don’t even know what you don’t know.”

While he has not become an expert on carbon-fiber reinforced polymer rod panels, Sigl has developed a working knowledge.

“I’ve been helped a lot by Mazen Hassan, doctoral student in Jawdhari research group. I’ve also been helping him in the lab on his project. As an undergraduate, you don’t know enough to be let loose in the lab.”  

But the other half of the equation is the joy that is found by developing new skills. “There is a big sense of accomplishment when you execute something complex.” Sigl referenced the sand coating of carbon fiber rods. “Once we got it done, it went well and I had a lot better understanding of the procedure. It’s a level of understanding you can’t get any other way without seeing it done or doing it yourself.”

Learning new bonding technologies

In the simplest terms, Sigl’s project involves developing technologies that could be used to strengthen girders or other concrete structures.

He said, “There are many regions with a significant number of structures needing rehabilitation or replacement. Traditional methods of rehabilitating flexural members can be very costly or not effective for long periods of time. To address this, carbon-fiber reinforced polymer rod panels arranged into short panels made continuous via finger joint locking and adhesively bonded to the soffit of deteriorating members can provide a simple and relatively inexpensive solution to this problem. 

“These panels can be made to be applied to a variety of beam types and lengths, which makes them a very flexible solution.”

The trick comes in bonding the carbon-fiber reinforced polymer composite rod panels to the original structure. 

Something better than epoxy?

Traditionally, epoxy has been used because of the excellent bond it forms between the panel and the strengthened member. 

However, there are drawbacks. Epoxy is a relatively expensive organic material, and its application requires strict safety precautions due to its potential toxicity during handling and curing. Also, epoxy bond performance can be severely compromised when the member is exposed to elevated temperatures, leading to premature debonding and reduced structural effectiveness. Furthermore, it can’t be applied when the surface is moist or cold.

The solution proposed by Jawdhari is using either traditional cement mortar or ultra-high performance concrete as an adhesive for carbon-fiber reinforced polymer rod panels.

Sigl’s experiments will look at four variables — length and diameter of the rod, surface roughness whether it is sand-coated or smooth and if traditional or ultra-high-performance concrete is used.

The rod length represents the minimum embedded length needed of the rods in a material to ensure that the material has an adequate grip on the material. The rods, varying in length from 9 to 13 inches, will be embedded into concrete poured into 2- to 6-inch-long sections of PVC pipe. A mechanical device will be used to pull the rod out of the cured concrete and determine the amount of force required to do so.

To return to project in the fall

At the end of April, the project was 40% complete. “We have a lot of the materials prepared, but we haven’t poured any concrete yet,” Sigl said.

With semester tests right around the corner, he doesn’t expect the project to go much further this spring. In the summer, Sigl has an internship at Raker Rhodes, a commercial structures engineering firm with an office in Sioux Falls. He will be back working in the structures lab in the fall and hopes to present at a student conference in the fall.

Jawdhari is pleased with the progress the recently green researcher has made. Jawdhari said, “It will be great if Keegan joins our graduate program and continues to Ph.D. and becomes a faculty member. The Future Innovator of America Fellowship provides great opportunity to receive graduate funding from the National Science Foundation.” 

Sigl encourages fellow students to “keep an eye on the Future Innovator program and apply. The research opportunity in the FIA will strengthen your application immensely, particularly if we conduct some of the tests and show your experience with testing and data analysis.  

Long term, Sigl envisions going to graduate school to focus on building design. After completing his professional engineering exam, Sigl is considering a return to academia and gaining a doctorate. He wouldn’t be the first engineering faculty member in the family.

Sigl’s great uncle is Arden Sigl, who taught civil engineering at SDSU for 38 years, retiring in May 2009.