Dr. Van de Riet and his students with the completed reef wall panels.
By Lisa D. Mickey
Nine third-year architectural students from the University of Kansas made the 19½ -hour drive to Florida for hands-on experience building Mangrove Reef Walls with their professor at Riverside Conservancy.
Dr. Keith Van de Riet, an associate professor of architecture at the University of Kansas, offered a summer professional elective class at the Riverside Conservancy Center in Edgewater, Fla. Students were able to spend a week in June constructing the unique product designed by their teacher as an alternative to conventional sea walls.
“Keith prepped us for this week in a studio class we had at Kansas in the spring,” said Lindsay Armstrong of St. Louis. “We did a concrete wall installation, so we have some background in mixing concrete and applying it to a wall, but definitely nothing to this scale.”
“We’re trying to figure out how to use concrete and create a habitat artificially for marine life,” added Armstrong, who will earn her master’s degree after five years of study. “Whereas what we did in Kansas was art, this is designed to function in the environment. It’s been really cool.”
Before pouring the mangrove reef wall panels, students assembled the molds and prepared an outdoor workspace where they would pour and cure the panels.
Prior to his current position at the University of Kansas, Van de Riet spent prior years on the water conducting research at Florida Atlantic University (FAU) in Boca Raton, Fla.
Focused on creating coastal structures to promote ecological habitat on developed shorelines, he molded the image of red mangrove prop roots built into his Reef-Wall panels. The idea was to provide not only a more natural aesthetic to a conventional sea wall, but to offer a more suitable substrate for the growth and maturity of marine life.
“The term ‘biomimicry’ has skyrocketed over the past couple of decades and now, we’re looking at nature for solutions,” said Van de Riet. “This is one where we’re looking at the formal qualities in nature – a flat sea wall – and transforming it into something more articulated, like a mangrove root system.”
His Mangrove Reef Walls incorporate a blend of high-strength Rapid Set concrete, “oyster flour” (crushed oyster shell) to temper the pH to attract oysters, and chopped-up coconut fibers as tensile reinforcement to prevent cracking.
Rather than just the flat surface of traditional sea walls, the textured and molded panels of the Reef Walls are designed to mimic multi-dimensional surfaces present in the natural environment.
Dr. Van de Riet preparing the concrete mixture to be poured into the molds. While the concrete was mixing, students added coconut fibers into the mixer.
Van de Riet fabricated the molds and brought them to Florida, where students built the boxes for the molds and set up the bolt holes and attachment points for the panels. During their visit to Riverside Conservancy, the students learned to mix and pour concrete into the molds, and then to prepare the molds for application to an existing sea wall using the proper hardware for support frames in a salt-water environment.
Working in the Florida summer heat and humidity, they also learned about the lagoon’s tides, as well as how salt water reacts to different metals.
“We teach them a lot of design with the computer in a lab or studio setting, but getting out for these types of projects is just priceless because the students really see the nuts and bolts of how things go together, while working on the sea wall and packing molds,” said Van de Riet. “They learn when things leak and how to recover from it. They learn how to do it right the next time.”
Students greased the mangrove reef wall mold by hand, making it easier to remove the concrete after it was poured and set. Allegedly, they seemed to have the most fun doing this compared to any other activity.
Danny Derouine of Chicago, was also involved in Van de Riet’s spring class in which students created “interesting shapes with concrete and fabric” for the Kansas wall installation. When he learned about the summer opportunity to work with the Reef Walls in Florida, Derouine signed up for the trip.
“At first, it was like an experimental, fun project, but this is real-world stuff,” said Derouine.
“I learned there is far more control doing concrete pours in a warehouse than here by the salt water,” he added. “We have to worry about the tide, make sure we’re using the right metals and make sure everything is sealed so it doesn’t rust in the water. It’s been really interesting to learn about these things.”
Derouine said a surprise benefit of the hands-on learning experience has been understanding how social and environmental impacts affect others in different places.
“That’s beneficial to understand when creating impactful architecture,” he said. “You have to have a good design element, as well as good function, and you have to work to achieve a balance between the two.”
Students applied a concrete mixture to the sea wall in an attempt to smooth the surface in preparation for anchoring brackets.
Armstrong agreed that hands-on experience in her educational training will make her a better architect in the future. Fifth-year, master’s-program architecture students at Kansas build a house. Before she does that, she will have had the experience of working with a product in a harsh, dynamic salt-water environment.
“I learn so much more by actually seeing it and doing it than seeing it on a screen in a classroom,” said Armstrong. “Definitely being here, putting everything together, learning about the tools used to assemble things and the ways things work, has been a great experience. It was totally worth the drive.”
As with any research project, Van de Riet warned the students in advance that the temporary installation of the Reef Wall panels might not work on the very old tabby-concrete sea wall at Riverside Conservancy. The students built the panels and bolted framing onto the aging wall, hoping the panels could be installed.
The goal was to display the product temporarily at Riverside Conservancy, demonstrating a product to the public and showcasing that the panels could be scaled up and the dimensions changed to suit different sea walls.
Dr. Van de Riet and students after having installed two brackets on Riverside Conservancy’s sea wall observed that there may be issues with anchoring the brackets securely enough to hold the weight of the concrete panels.
“All technologies are always changing and construction is always changing,” said Van de Riet. “This product is a stepping stone and if we can take steps toward something that is more sustainable, eventually we will get to something that is truly regenerative.”
But as expected by their professor, the old tabby wall could not support the anchor bolts. The wall also was not “plumb,” so getting the panels on level plane proved difficult. Students were there with their professor to learn a beneficial lesson.
“Things don’t always go as planned and we knew we were up against a big challenge with this wall,” said Van de Riet.
But while he and the students were disappointed, their hand-on work had rendered a valuable experience with a greater understanding of their overall objective.
“The real important lesson here is that this is part of a bigger effort for sustainability,” said Van de Riet. “We may have lost the battle here this week, but we’ll win the war.”
For more information, visit: www.reefwall.com.