Advanced building structure offers real chemistry
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When it comes to team chemistry, UW–Madison is well aware of its benefits on the athletic field, but the university also knows how central the academic discipline of chemistry is to its educational mission. The UW is in the process of updating its chemistry facility to prepare for the next generation of chemical education, and it’s doing so with the help of an advanced structural system.
The $133 million building project, a combination of renovation and new construction, has been a capital construction priority for 10 years, but it’s also propelled by a recent enrollment surge in the UW’s chemistry program and an interest in implementing more active learning in lab courses. According to chemistry professor Robert McMahon, who serves as the building committee co-chair, while more than 2,200 students are specifically enrolled in the chemistry program, the university now teaches more than 7,000 students per semester in undergraduate chemistry classes, and over half of all undergraduate students will take at least one chemistry class during their time on campus.
At the moment, these courses can be bottlenecks for students, prevent timely graduation, and limit additional enrollment. The university is fortunate to have the opportunity to redesign the facility at the same time it is revamping its undergraduate curriculum, so it’s trying to have these two parallel processes “inform each other,” McMahon says.
However, that’s not the only rationale. “The important thing to emphasize is that this is not just about chemistry majors,” McMahon notes. “It’s about the whole cohort of undergraduate students who require chemistry for their own major in the STEM disciplines, as we call them. Chemistry is foundational to all these different majors, which includes health sciences, medicine, dentistry, pharmacy, nursing, as well as biology, engineering disciplines, and other science and engineering majors.”
A new nine-story tower along University Avenue primarily will be used for undergraduate and teaching labs, instructional labs, and lecture rooms, and there will be renovation of three floors of the existing structure, at 1101 University Ave., which is where the instructional program now resides. There is a practical, safety-related need, as well, because it might surprise Madisonians to know that the two oldest wings of the building do not have fire sprinklers.
The irony is not lost on McMahon. “If there is any building in Madison that you thought would have fire sprinklers, it might be the chemistry building, but it doesn’t,” McMahon states. “So, we’re going to have fire sprinklers installed and a fire alarm upgrade through the entire complex, and we’re also having a major replacement of the HVAC systems in the existing building. So, these safety considerations are the other drivers in addition to the enrollment issues.”
Filling the void
The voided-slab ("bubble deck") system used in construction of the new UW chemistry building will displace concrete with reinforced plastic spheres, making the building lighter and saving approximately 1,610 cubic yards of concrete and roughly 44 tons of steel. Photo: Mortenson Construction
Contributing to building safety is a structural system featured in the new tower, a flat plate–voided concrete slab system also known as “bubble deck.” These systems, invented by Danish engineer Jorgen Breuning, have been around since the 1990s but have been more often deployed in Europe. They most often are used in hospitals and academic buildings, but they can be used in industrial and residential construction, as well. In Europe, they also are deployed in condominiums and even some parking garages.
GRAEF, the Milwaukee-based engineering firm, was the first to bring voided-slab systems to the United States. As explained by structural engineer Dan Windorski, a project manager for GRAEF, these are two-way voided slabs, which means the slabs can span in both directions. They are essentially made up of columns and a uniform concrete slab but without beams or drop panels, and they are the thinnest floor structure possible without post tensioning — high-tension cables — added to the system.
The systems displace concrete that serves little structural purpose with reinforced plastic spheres, making buildings lighter and, in the case of the chemistry building, saves approximately 1,610 cubic yards of concrete, which works to about 180 fewer truckloads of concrete to the job site, and saves roughly 44 tons of steel (including reinforcing bar, or rebar). The systems are not only marginally more economical — saving 1 to 2 percent on total project cost — their floor systems offer fire proofing and they are more energy efficient and result in better building performance in terms of sound and vibration control.
As GRAEF project manager Bryant Stempski notes, the thinner floor structure offers the advantage of an additional story for commercial buildings in Madison, which face height limits. The extra floor, and the extra square footage it brings, can be the difference in making a project financially viable. “You can get more floors as your structure can be thinner than some conventional buildings with a steel system,” Stempski explains. “This is about half as thick as a steel floor system.”
With the chemistry building, there will be some remodeling limitations, but McMahon notes that if spaces are property designed beforehand, that shouldn’t be an issue. “In the past with our experience, we just have a concrete slab in our existing buildings,” he notes. “So, if we want to remodel a lab after the fact and put in another sink or drain, it’s no problem to just drill a hole in the floor. Now we realize the floor itself is a very sophisticated design and you need to be careful about getting everything in there in the first place because it’s all designed as a system. We’re not going to have the same kinds of flexibilities down the line in terms of remodeling, but we just pay attention to that up front and hopefully we’re in good shape.”