Civil Engineering Research Aids High School Gym

A structural engineering solution devised by UA civil engineers has allowed the Coolidge School District to add elevated bleacher seating to its Roundhouse Gymnasium at minimal cost and disruption to school activities.

The technology involves strengthening ceiling beams with Fiber Reinforced Polymers (FRPs) that are similar to fiberglass and Kevlar.

QuakeWarp, Inc., a company formed by UA Civil Engineering Professor Mohammad Ehsani, has employed FRPs in the past to strengthen concrete beams and columns, reinforce masonry walls, and retrofit large pipes.

The process has been used in California to help masonry structures resist earthquakes, and in Arizona to strengthen floors in local hospitals and to line pipes for the Central Arizona Project.

New Bleachers Create A Problem
In Coolidge, Ariz., the school district wanted to create elevated bleacher seating above the locker rooms that are next to the gym floor. This would allow them to move sports fans off the gym floor and to provide them with a better view.

Unfortunately, placing this kind of load on top of the locker rooms wasn't anticipated when the gym was built in the 1960s. School officials found that the second floor wouldn't support the bleachers and spectators without being reinforced.

One possible solution involved placing vertical columns under the floor, but this would have severely restricted space in the locker rooms. Another solution would have added additional horizontal beams below the floor, but these would have been costly and difficult to install.

So Paragon Structural Design, Inc., of Phoenix, Ariz., which was in charge of structural engineering on the project, contacted Ehsani about using FRPs to do the job. Mark Larsen, president of Paragon, was familiar with the process as an alumnus of UA Civil Engineering.

Problem Sends Ehsani Into the Lab

A retrofitted test beam nears failure in UA's Structural Engineering Laboratory.

Larsen's question sent Ehsani into the lab to test glue laminated (glulam) wooden beams similar to those used in the Roundhouse gym. Ehsani worked on this research with civil engineering master's student Nathan Palmer, who was very familiar with the Roundhouse, having played on the Coolidge basketball team just a few years before.

Ehsani and Palmer tested wooden beams similar to those used in the Coolidge gym, and used strain gauges to measure forces. The gauges were mounted on an unmodified beam and on a second beam reinforced with FRP materials. They found that the reinforced beam was 67 percent stronger than the unmodified one.

With this data in hand, work began on the Roundhouse gym.

Carbon-fiber plates were epoxied to the top and bottom of the wooden ceiling beams to increase their strength in both tension and compression. Carbon fabric was then wrapped around the beams to anchor the carbon plates and to provide increased shear strength by confining the laminated wood.

Adding the carbon-fiber plates to the tops of the beams was a problem because the beams were flush with the floor above and not accessible.

Novel Idea Solves the Problem

This cross-sectional drawing of a glulam beam shows how the carbon-fiber plates (solid lines) and carbon sheeting (hatched lines) were added to the glulam beams.

Ehsani and Palmer solved this problem by cutting 1/8-inch-wide slots 1 5/8ths inches deep into the beam near the top. The slots were slightly offset to prevent weakening the beam. Then 1.5-inch-wide strips of carbon plate were coated on both sides with thixotropic epoxy and pushed into the grooves.

A 40-mil-thick layer of thixotropic epoxy was then applied to the beams, and carbon fabric, which had been saturated with epoxy resin, was wrapped around three faces of the beam.

The beams were retrofitted in less than two weeks — while the locker rooms remained in use — at a cost of $8.50 per square foot.

"This was a very inexpensive solution," Ehsani said. "Sometimes floor tiles used as floor covering can be more expensive."

The Roundhouse floors, which originally were designed for loads up to 40 pounds per square foot, can now handle loads up to 60 pounds per square foot.

Pioneering the Technology Pays Off
"The greatest pleasure for one's professional career is to have dreamt of some solution and pioneered the field and then be lucky enough to be alive to see that it gets used." Ehsani said. "It's just a real joy when I drive by some building and I see that we actually strengthened it with something that came out of our lab."

Ehsani and UA Civil Engineering Professor Hamid Saadatmanesh pioneered the use of FRPs in construction beginning with a 1986 exploratory research grant from NSF.

"For the first six or seven years, people thought this was a really crazy idea," Ehsani said. "We were funded under an exploratory research grant because the idea of using FRPs to retrofit and strengthen structures was considered very far out at that time."

But Ehsani and Saadatmanesh proved the skeptics wrong and that first grant led to a patent on the process. When the researchers wanted to take the results from their lab to the field for further testing, Ehsani formed QuakeWarp for liability reasons.

Working at the interface of research and application has proven beneficial both to research and teaching, Ehsani said.

"I wouldn't have delved into this mini research project on glulam beam strengthening, for instance, if it were not for this project in Coolidge High School," he said. "This is something we had not looked at before. And we tested it and found out that it works and now we are publishing papers on it and have solved the problem for the client."

By working closely with practicing engineers, Ehsani said he has gained a deeper understanding of factors that are important in industry, but may not be important in the lab.

"Oftentimes for contractors, the aesthetics — the smell, how much dust is generated and similar issues — are critical," he said. "So is the ability to quickly complete the job and move out. In the lab, these things often aren't important. But they've now become critical factors in our research and they're real-world engineering concepts that I include when teaching my classes."

"It's been very gratifying to me to see the fruits of our research being applied and benefiting people," he added. "It's much better than just having your research end up in a publication that's sitting on somebody's shelf."

Students Can Cash In on Mining Engineering

Students take a break during a mining and geological engineering field trip.

Mary Poulton is like the millionaire who tries to give away hundred-dollar bills. Everyone thinks there's a catch.

While she's not tossing greenbacks in the air, Poulton is offering something that's almost as good, or maybe even better, than free cash — careers in mining engineering.

And there's no catch to it — just skyrocketing demand.

Consider that last year UA graduated five mining engineers. Most of them received at least four job offers, which often included incentive packages. The average starting salary was $55,000 a year, without overtime or bonuses. One recent graduate received an offer as high as $80,000 a year. That was with a bachelor's degree and very little experience.

Poulton, head of UA's Mining and Geological Engineering (MGE) Department, says despite the cyclical nature of the resources industry the demand for mining engineers is high for two reasons.

First, consumption of natural resources is at an all-time high. Production can't keep pace and new mines can't open fast enough to satisfy the market.

China, and to a lesser extent, India, are responsible for the huge demand. The Chinese have greatly increased their consumption of coal, iron ore, cement, steel, scrap copper, mined copper and other resources that support basic infrastructure development and manufacturing.

"I spent a month in China in March and I have never seen such a frenzied pace of growth, " Poulton said. "The bridge building, the road building and the power infrastructure development are running at an incredible pace. Some estimates are that this high level of consumption could continue for the next 10 to 20 years."

Second, the mining industry is graying. Sixty percent of SME (Society of Mining, Metallurgy and Exploration) engineers are past 50. Meanwhile, only four percent of the membership is under 30.

The same graying is occurring among USGS scientists, mining engineering professors, petroleum engineers and heavy-construction engineers. Large numbers of mining engineering graduates are needed just to replace those who are retiring.

Profession Faces a Crisis
"Mining engineering is in a crisis," Poulton said. "But, as in any crisis, there's also opportunity. It's a great time to get into the field because not only do students have their pick of really interesting jobs in just about any location, but — because of this big retirement bubble — recent graduates are being groomed on the fast track for management positions — much faster than we've seen in the past."

UA students have an added advantage in this market. The mining industry looks first to those programs, such as UA's MGE department, that have a long history of producing mining executives.

The Princeton Review Gourman Report has rated UA's mining engineering program second in the nation. The department has one of the world's strongest research programs in mining technology and it owns the San Xavier Mine, where students get hands-on experience in hard-rock mining.

So with the high salaries, multiple job offers and excellent prospects for advancement, why aren't more students enrolled in mining engineering? Last academic year, only about 110 students graduated with mining engineering degrees nationwide.

It's Not a 19th Century Throwback
"It's an image problem," Poulton said. "Many people mistakenly think that mining engineering is some kind of throwback to the 19th century — low tech and environmentally destructive. It's like describing electrical engineering in terms of vacuum tubes."

Actually, "mining engineering" is a misnomer these days, Poulton added. "Mineral resource engineering" or "resource engineering" better describe the profession because mining engineers often support activities that have nothing to do with mines. Many of them work in the construction industry, building subway tunnels or excavating skyscraper foundations and bridge pilings.

"There are opportunities for our graduates in the financial sector, the environmental sector, and a broad range of industries," Poulton said. "The MGE Department is not just about mining, it is about the way the future is built.”

In fact, UA's mining engineering program is developing a new three-track curriculum that reflects the broad range of jobs that mining engineers tackle.

First is the traditional mining operations track, which is still in high demand. Second is a geomechanics track to meet the increased demand for heavy-construction engineers. Third is a sustainable resources track that involves courses in health, safety, and the environment.

Counter to the 19th-century, low-tech stereotype, mining is more like rocket science these days, Poulton explained. It's heavily computer-based and automated. In some underground mines, all the operations are controlled from the surface and robots are the only ones working underground.

"Today's mining engineers not only have to be well versed in earth sciences, environmental design and human factors, but they also have to be technology specialists," Poulton said. "They have to understand wireless technology, GPS, all sorts of information technology, sensors and control optimization. It's really a much different industry than it was even 20 years ago."

Fighting the Stereotypes
Many students also don't consider mining careers because of bias in the media and in some pre-college curricula, Poulton said.

"I have reviewed textbooks from a number of publishers, and the content on mining tends to be, limited and very out of date," Poulton said."You often don't see positive images of mining in the media either," she added. "If there's a violation of a water or air permit, it's front-page news. But you never hear the positive things that go on with mining or the vital contributions it makes to the economy and national defense.

"Also, there are some absolutely stunning examples of reclamation that never make it into the media or the textbooks. And today's mining companies are working closely with communities to ensure that they will have healthy economies once the mineral deposit has been depleted and the mining company moves on."

Another problem is that there's no obvious path from high school into mining engineering programs, Poulton said. "Quite often engineering students are recruited from an affiliated high school science discipline. Chemical engineering students frequently are those who had a strong interest in high-school chemistry. Mechanical and electrical engineers come out of the physics classes. But a lot of high schools don't offer earth science courses. So there's no natural transition for students to go from high school into mining engineering."

Poulton and others in UA's MGE Department are working hard to get the word out about the breadth of career opportunities for mining engineers and to increase enrollment.

"Mining engineering programs across the country need to graduate three to six times more students than they do today just to meet the current and future demand for mining engineers," Poulton said.

"These workforce issues go far beyond the health of individual companies," she added. "Congress is very concerned about the shortage of mining engineers and the effect of that shortage on the economy and national security."

Hi-Tech Hot Rod is the Ultimate Learning Lab

UA's formula car roars through a corner during a driver training session.

Hot rods have led many students to mechanical engineering careers and these days a high-tech hot rod — UA's screamin' formula car — is keeping some students in school.

"I would not be an engineer and I would not be in school right now if it weren't for this (SAE formula car) club," said Dustin Wright, the team's director of manufacturing. "When I ran into this club, I was so frustrated with engineering and college in general that I was ready to quit. I was spending all this time in class and getting nothing out of it."

"These student projects (formula car, mini-baja vehicle, solar car, etc.) keep people in school," Wright added. "They keep students motivated, and they give them an outside interest that they learn from."

The Ultimate Lab Class
In fact, the UA formula car just may be the ultimate lab class.

Freshmen and sophomores learn complex computer analysis and other sophisticated skills from the club's upper classmen. And when they meet these concepts in class as juniors or seniors, the classroom work is more like a review than a new learning experience.

Dustin Wright, formula car team manufacturing director, explains some of the car's features during a presentation to sponsors in December.

"We've developed our own computer tools that we teach team members to use," Wright explained. "And we also teach fundamental things. For instance, we have a welding class that I teach every morning at 8 a.m., where our members learn TIG welding."

The club also extends its teaching to Tucson's grade schools and middle schools, where team members explain and demonstrate the car.

Educating Younger Students
"One of our biggest goals is to educate younger students, as well as the community, about what we do and how they can get involved in higher education and engineering," said formula car Team Captain Ryan Kanto. "We

Jon Schwab (left), the formula car team's director for electronics, talks with team member Chris Bunch before a driver practice session.

also talk about alternative fuels because our car runs on ethanol, which is made from corn."

A lot of learning also happens as the 140 or so formula car teams that participate in the annual SAE formula car competition share test data, tools and other information.

"All of the teams realize that this isn't a competition with other teams," said Ryan Kemmet, marketing director for UA's formula team. "Maybe the top ten teams are going to keep some of their information proprietary and aren't going to share it, but most teams will gladly share information because building a formula car is a learning experience, not an all-out effort to win."

"We've already shared really valuable information and tools with other teams, and it's only to our benefit because they help us in return," Kemmet added.

Engine Tests Improve the Car
Many teams even post vital design information on the Internet.

Among other things, UA team members picked up valuable test data on the Suzuki motorcycle engine that powers their car. Four teams from other universities ran similar engines on test stands, twisting them and measuring critical clearances, as well as engine life.

"Basically, they found that the engine is perfectly fine when used as a stress member in the frame," Wright said.

Last year, UA's team didn't use the engine as a stress member because others had told them it couldn't stand the abuse. With this new data, the engine crankcase in the 2005 car has been included as a load-bearing member in the frame. This and other changes have helped cut the frame weight from 67 pounds to 45 pounds.

The team also has developed an accurate computer model of the engine as part of an overall effort to reduce development time.

No More Mistakes
"Our primary goal at the end of last year was to say, 'Look, we don't want to make any more mistakes,' " Kanto said. " 'Mistakes are great and we learn from them, but if we're going to build a car, let's try to build it right the first time so that we don't have to waste our time with rebuilds.' So everything now is run through the computer. The parts are tested and weighed. We do finite element analysis on everything so we know the parts are not going to break before we build them."

Often these parts are then tested in the 2004 car, which has become the team's rolling test bed and driver-training vehicle.

The team also has used the engineering college rapid prototyping equipment to quickly build mock-up parts to be sure that parts will fit before they're machined. In other cases, the rapid-prototype parts have served as male molds on which carbon-fiber parts are built. Once the part is completed, the mold is dissolved out leaving the carbon-fiber shell. The team used this method to build the formula car's intake manifold.

Simple Solutions to Complex Problems
Concentrating on computer modeling and project engineering instead of cut-and-try fabrication has given the team more time to find elegant solutions.

"We've had more development time this year, and we've been able to find simpler solutions to complicated problems," Wright explained. "It's really easy to find a complicated solution to a simple problem: doing the opposite is very difficult."

"But that's not to say that this car is low-tech," Wright added. "It has a carbon-fiber stressed skin and riveted aluminum seat. We've taken aircraft technology, a lot of aerospace industry technology, and applied it to this car."

All of which has been a great learning experience.

"All I can say is that building this formula car has been the most fun I've ever had in school," Wright said. " I've learned almost more from working on the car than I have from my engineering classes.

"For me, this is the closest to industry experience that I've had in school. I've had internships and things like that and, to be quite honest, none of them were as rewarding as this. With internships you do get a paycheck and we don't get paid for working on the formula car. But this car has really motivated and driven us.

"Internships feel more like work and building this car just feels like fun."

Engineers Resurrect a 900-year-old Technology

These tiny pieces of Ru-glazed pottery were mounted on a slide before being analyzed under the scanning electron microscope in UA's Materials Science and Engineering Department.

The last Chinese potter who knew how to create a translucent, blue-green glaze known as "Ru glaze," died more than 900 years ago.

The secrets of this highly prized glaze died with him.

Today, fewer than 100 Ru-glazed ceramics exist. Not many were made because Ru ware was reserved for the 10th to 12th century imperial court, and none has been made during the past 900 years because no one has been able to reproduce the technology that created this delicate, opalescent finish.

That may soon change. University of Arizona engineers are using scanning electron microscopes, molecular-level understanding of materials and a knowledge of high-tech ceramics to time travel through bits of existing Ru glaze for a peek back into 12th century China.

"People have tried to produce Ru glazes, but haven't succeeded," said Alix Deymier, a junior in Materials Science and Engineering, who is working with MSE Professor Pamela Vandiver to unravel the secrets of Ru glazing.

"But we hope to bring back that knowledge," she said.

Alix Deymier is using this scanning electron microscope to study the molecular structure of Ru glazes.

Extensive analysis of the Jun glazes — which were used both before and after Ru glazing — has given Deymier and Vandiver some clues. Many thought the Jun glazes, which are bluer than Ru glazes, were produced with manganese or other chemicals. But Vandiver discovered that the color is caused by what materials scientists call a "liquid-liquid phase separation."

Jun glazes are actually a form of glass, and materials scientists know that glass behaves more like a liquid than a solid at the molecular level. Glass doesn't have a lattice structure and is more amorphous, so it has many of the same properties as a liquid.

A liquid-liquid phase separation is like mixing oil and water, Deymier explained. "If you mix them, the oil makes small droplets within the water," she said. "Well, this is the same thing that's happening with Jun glaze. There are two glasses and one is forming inside the other. That's causing scattering centers and refraction at interfaces between the glasses, which are scattering the light and making it look blue. So it's not a chemical, but the microstructure of the glaze that's creating the color."

Deymier and Vandiver put a tiny sample of Ru glaze under a scanning electron microscope after etching the glaze with acid and found the same kind of pits they see in Jun ware, which are the telltale signs of a liquid-liquid phase separation.

This sample of Ru-glazed pottery is about one inch square and more than 900 years old.

Vandiver tried to replicate the composition of Jun glaze and then fired these samples at different temperatures. After that, she analyzed the microstructure of the various samples and produced a phase diagram that shows where in the compositional range the liquid-liquid phases occur and how to relate their microstructure to the firing temperature.

"We're now trying to look at the microstructure of the Ru glaze to determine where we can place it on this phase diagram," Deymier said.

But first they need to know the chemical composition of Ru glaze. Glazed ceramics are fired twice. They're fired before the glaze is added to harden the ceramic. Then the chemicals that will create the glaze are brushed on the ceramic's surface or the ceramic may be dipped in the chemicals. Then the object is fired a second time to create the glazed surface.

Deymier and Vandiver plan to use an electron microprobe in UA's Lunar and Planetary Laboratory to determine the exact composition of their Ru glaze samples. "We are using the electron beam microprobe because we need to know the composition as well as the microstructure of the glaze before we can place the Ru ware on the phase diagram," Deymier said.

"We'll analyze the glaze from the outside to the inside to see if there's a variation in composition through the sample and then we'll test the different samples to see if the composition varies from sample to sample," she added.

"We want to see if the Ru ware from different locations is different," she said. "We want to see how much variation there is in the pottery that's all classified as Ru ware."

The researchers are using Ru pottery samples that were donated by museums and by other researchers who hope the UA team will be able to bring this technology back from the past.

Unraveling the mysteries of Ru glazing began as a class project for Deymier when she was taking a scanning electron microscope lab in the MSE department. It's now turned into an ongoing research project.

"We're hoping that by discovering these things — the temperature at which the glaze was fired and its chemical composition — that we'll be able to replicate and bring back the knowledge of how Ru ware was made," Deymier said.

Engineers Help to Save and Reconstruct the Past

Anthropology master's student Ned Gaines demonstrated flint knapping, a method for making stone tools, during a lab in MSE 257, one of the classes in the new Heritage Conservation Science Curriculum.

Each time an ancient vase disintegrates, a ceramic tile crumbles or a painting cracks and fades, another link with our past is lost and we understand just a little less about where we came from and, ultimately, who we are.

When the last artisan dies and an ancient technology is lost, we're similarly impoverished, says Pamela Vandiver, an internationally recognized expert in artifact preservation and, now, a professor at The University of Arizona.

Vandiver came to UA last year to start a program in Heritage Conservation Science (HCS) that trains students to stabilize, preserve and better understand ancient artifacts and how they were created and used.

The curriculum, which combines engineering, anthropology, architectural history and art history is particularly important today because many of the material links to our past are disintegrating, while the ancient technologies that created them are disappearing.

"To preserve our inheritance, we really need a group of scientists and engineers who can work with conservators and other experts to stabilize and preserve these objects," says Vandiver, who holds a joint appointment in Anthropology and in Materials Science and Engineering (MSE).

Professor Pamela Vandiver talks with a student during a lab class on flint knapping.

Knowing how these objects were made is just as important as preserving them, she added.

We might wonder what there is to understand. After all, we live in a high-tech, materials-oriented culture that can produce everything from ceramic heat shields for space shuttles to atom-sized electronic circuits. So there can't be much we don't know about making things, right?

“Wrong,” says Vandiver. For instance, the glazes on 10th to 12th century Chinese ceramics are a mystery. They're at the top of the heap in terms of stable, high-fired ceramics. But modern potters can't reproduce them.

In another case, we didn't understand the technology behind 12th century ceramics made at the recently excavated imperial kilns in Angkor Wat until last year when Vandiver and her Cambodian colleagues unraveled the process.

Khmer potters fired a quartzite-rich ceramic body and then re-fired the ceramic using a Chinese-style glaze. It was either a high-lime, green celadon glaze or a high-lime and iron brown glaze. The glazes were fired to between 1,800 to 2,000 degrees Fahrenheit. Celadon glazes have a translucent quality that is meant to resemble jade.

This ancient Cambodian technology now is being taught to local potters who are keeping it alive by producing reproductions of the 12th-century ceramics.

Heritage Conservation Science involves learning how artifacts are handcrafted. A student made this glass vase during a lab that explored the technology of glass blowing.

The technology has been so exactly replicated that "some of the border guards have started to intercept these new ceramics because they look exactly like the old ones," Vandiver says. "So we have succeeded in re-creating an important technology and keeping it alive."

Preserving ancient technologies is so important that UNESCO recently started an international program to preserve craft knowledge, Vandiver says. The program is similar to the one that designates World Heritage Sites.

Vandiver came to UA because much of the basic infrastructure needed to start an HCS program already existed on campus. Architecture has a degree in architectural preservation. Archaeology is a strong discipline at UA, and the university has world-recognized tree-ring and carbon-dating labs. The Arizona State Museum is a center for conservation of Southwestern artifacts, and UA has materials-based studies in art history, chemistry, classics, geosciences, and Near Eastern studies.

In addition, UA has a long history of socio-cultural studies and interdisciplinary cooperation between the MSE Department, Anthropology and other programs.

For Vandiver, UA was the ideal location to transfer her work after 18 years as a senior research scientist at the Smithsonian and as a MSE faculty member in the cultural heritage program at Johns Hopkins University.

The Johns Hopkins program was discontinued when two key professors retired, and Vandiver also found herself being kicked upstairs into administration at the Smithsonian.

"So I couldn't go on excavations, couldn't work in the lab, and couldn't work with students," she says. "It was getting more and more frustrating all the time."

She knew about the critical mass for heritage conservation science at UA because her former Ph.D. thesis supervisor, the late David Kingery, was on the UA MSE faculty for many years and organized collaborative research on historic preservation.

So she decided to follow her passion, discarding a prestigious senior position at the Smithsonian to start a new program at UA.

"We're trying to put materials science education at the core of historic preservation, rather than just wallpapering over an archaeologist or conservator with a few materials science courses," she says. "We are producing students who are truly dual disciplinary."

Currently, she and her students are working on several projects. These range from studying lost glazing technologies used on 12th-century Chinese pottery to unraveling the mysteries of a Hopi pottery style.

The projects also include studying adobe-making technologies and constructing kilns to better understand glass slags and Greek pottery. Another project involves studying the basic physics related to cleaning artifacts with lasers. To read more about these projects, click here.