Neil Armstrong Distinguished Visiting Fellows
The prestigious Neil Armstrong Distinguished Visiting Fellows program brings highly accomplished and recognized scholars and practitioners to the college to catalyze collaborations with faculty and students.
Fellows are individuals who have been eminently recognized for their impact and achievements in engineering or related disciplines, who collaborate with Purdue Engineering faculty members on research projects and initiatives including new research directions, industry engagement, on-campus and online educational efforts, increasing diversity and inclusion, as well as entrepreneurship. Their selections are based on nominations made by faculty and the proposed impact of their research and visit on Purdue Engineering.
Neil Armstrong Distinguished Visiting Fellows Fireside Chat
Purdue Engineering held a Virtual Fireside Chat of our Neil Armstrong Distinguished Visiting Fellows on April 20, 2022, via Zoom.
News
Faculty share research, ideas in new distinguished visiting fellows program
The Neil Armstrong Distinguished Visiting Fellows program began in March 2019, bringing highly accomplished and recognized scholars and practitioners to collaborate on work with engineering faculty and students. These professionals visit for several weeks a year over the course of three years.
This year marks the 50th anniversary of Armstrong becoming the first man to walk on the moon as commander of Apollo 11. He earned a bachelor’s degree from Purdue in aeronautical engineering in 1955 and was awarded an honorary doctorate in engineering from Purdue in 1970.
Arvind Raman, senior associate dean of the faculty, said the inaugural cohort of visiting fellows is highly recognized and represents expertise in diverse areas ranging from heterogeneous catalysis, jet fighter design, remote sensing, construction and hydrology.
“Purdue Engineering is proud to launch this program to bring highly accomplished and recognized scholars and practitioners to Purdue Engineering to catalyze collaborations that can lead to increased impact and visibility for our visitors and their faculty hosts, schools/divisions, and college,” said Raman, the Robert V. Adams Professor in Mechanical Engineering.
The visitors in the first cohort are all National Academy of Engineering members and include:
- Enrique Iglesia, of the University of California, Berkeley, researches catalysts — compounds that speed up or facilitate specific chemical reactions. His work involves synthesizing inorganic solids that are useful as catalysts for transforming molecules into chemicals and fuels.
- Dara Entekhabi, of the Massachusetts Institute of Technology, is an expert in hydrological remote sensing and serves as science team leader for the NASA Soil Moisture Active Passive satellite mission.
- Paul Bevilaqua, formerly at Lockheed Martin, is renowned for inventing the vertical lift concept in the F-35 Joint-Strike Fighter during his time there.
- Randall Poston, of Pivot Engineers consulting firm in Austin, Texas, has championed the repair of existing structures for upward of 30 years and is one of the preeminent structural consultants in the U.S.
- Andrea Rinaldo, of Ecole Polytechnique Fédérale de Lausanne, is renowned as co-founder of the field of Ecohydrology (interactions between water and ecosystems) and for his theory of self-organized fractal river networks and efficient transport networks.

A College of Engineering alumnus famous for his “one small step” will be honored through a new program intended to bolster Purdue University’s impactful engineering research, engagement and education.
Suresh Rao, the Lee A. Rieth Distinguished Professor in Environmental and Ecological Engineering, said collaborations with Rinaldo will entail areas related to sustainability of natural resources, and influences of socio-economic systems on eco-hydrological processes.
“As an alum of Purdue Civil Engineering, we are excited to have Dr. Rinaldo return and re-engage with faculty and students in the College of Engineering and across the campus,” said Rao, who is hosting Rinaldo. “The range of his intellectual contributions to general theories of scaling and networks in natural systems would be of interest to a broad spectrum of Purdue colleagues.”
Julio Ramirez, the Karl H. Kettlehut Professor of Civil Engineering, said he looks forward to hosting Poston and the benefits he will bring to the Lyles School of Civil Engineering.
“Dr. Poston’s visit will energize and challenge our students, while simultaneously serve as a catalyst for innovation with our faculty and professional staff,” he said.
James Garrison, a professor of aeronautics and astronautics at Purdue, said he will host Entekhabi with the intent on researching new satellite mission concepts for globally mapping sub-surface soil moisture and snow. Entekhabi also will be involved with a two-part course for undergraduate and graduate students in fall 2019 and spring 2020, Earth Observation Mission Design – the definition of a venture class NASA Earth science mission.
Tom Shih, the J. William Uhrig and Anastasia Vournas Head of the School of Aeronautics and Astronautics, plans to collaborate with Bevilaqua on aerodynamics, aeroacoustics and new concepts in aircraft design. Bevilaqua also will review undergraduate design projects and participate as a panel member on ethics for undergraduate students.
Iglesia will work with faculty and students involved with the Center for Innovative and Strategic Transformation of Alkane Resources (CISTAR). He will be hosted by Fabio Ribeiro, the Norris and Eleanor Shreve Professor of Chemical Engineering and director of CISTAR.
“Professor Iglesia’s unerring ability to reduce complex problems to their most fundamental aspects, use quantitative relations between those underlying features to solve the problem at hand, and then to generalize the solution to provide predictive design principles has provided an unprecedented breadth of field-defining concepts in heterogeneous catalysis and practical solutions to grand challenge problems related to energy and the environment,” Ribeiro said.
Participants were nominated from College of Engineering faculty as well as endorsements by Engineering school heads and Mung Chiang, the John A. Edwardson Dean of Engineering. They were selected, in part, based on the likelihood of impact of the nominee’s visit on research and education at Purdue.
Program coordinators anticipate as many as three new visiting fellows to be announced each year.
During their visits, the scholars will collaborate with Purdue Engineering faculty on research projects, and/or on broader school or college priorities including new research directions, industry engagement, on-campus and online educational efforts, increasing diversity and inclusion, as well as entrepreneurship.
The visits are expected to begin in March with Rinaldo.
The visiting scholars will stay a total of up to three months through 2021. The time can be taken in multiple visits.
The host is expected to organize events such as workshops during the visit.
Upcoming Events
Photonic Time Crystals Crash Course
Lecture — February 21, 2022 at 10:00am-11:00am
Birck Nanotechnology Center, Room 1001
Registration Link
Abstract
Photonic Time Crystals (PTCs) are dielectric media whose refractive index is modulated periodically in time at time scales of an optical cycle. These systems conserve momentum but not energy, and are characterized by momentum bands and bandgaps, where the amplitudes of their eigenmodes can increase (or decrease) exponentially. Prof. Segev will introduce the fundamentals of PTCs, discuss the topological features of waves propagating in PTCs, localization in PTCs containing disorder, and spatiotemporal photonic crystals as well as their impact on both the fundamental science of light and photonic applications.hotonic Time Crystals (PTCs) are dielectric media whose refractive index is modulated periodically in time at time scales of an optical cycle. These systems conserve momentum but not energy, and are characterized by momentum bands and bandgaps, where the amplitudes of their eigenmodes can increase (or decrease) exponentially.
Biography
Mordechai(Moti) Segev is the Robert J. Shillman Distinguished Professor of Physics, at the Technion, Israel. He received his BSc and PhD from the Technion in 1985 and 1990. He joined Princeton as Assistant Professor in 1994 and became Professor in 1999. Then Moti went back to Israel and was appointed as Distinguished Professor in 2009.
Photonic Time Crystals Seminar
Seminar — February 21, 2022 at 11:30am-12:30am
Birck Nanotechnology Center, Room 1001
Registration Link
Abstract
Photonic Time Crystals (PTCs) are dielectric media whose refractive index is modulated periodically in time at time scales of an optical cycle. These systems conserve momentum but not energy, and are characterized by momentum bands and bandgaps, where the amplitudes of their eigenmodes can increase (or decrease) exponentially. But more interesting than all the rest - Prof. Segev will discuss the classical and quantum features of light emission in PTCs from various radiation sources, such as free electrons, classical dipoles, quantum fluctuations, and the emission by atoms. The latter opens new avenues for making widely tunable lasers that extract energy from the temporal modulation of the medium. hotonic Time Crystals (PTCs) are dielectric media whose refractive index is modulated periodically in time at time scales of an optical cycle. These systems conserve momentum but not energy, and are characterized by momentum bands and bandgaps, where the amplitudes of their eigenmodes can increase (or decrease) exponentially.

Class of 2021 Fellow
Mordechai “Moti” Segev is the Robert J. Shillman Distinguished Professor of Physics and Electrical Engineering, at the Technion, Israel. He received his BSc and PhD from the Technion in 1985 and 1990. After postdoc at Caltech, he joined Princeton as Assistant Professor (1994), becoming Associate Professor in 1997, and Professor in 1999. Subsequently, Moti went back to Israel, and in 2009 was appointed as Distinguished Professor.
Moti’s interests are mainly in photonics, solitons, lasers, and quantum optics. He won numerous international awards, among them the 2007 Quantum Electronics Prize of the European Physics Society, the 2009 Max Born Award of the Optical Society of America, and the 2014 Arthur Schawlow Prize of the American Physical Society. In 2011, he was elected to the Israel Academy of Sciences, in 2015 to the National Academy of Science (USA), and in 2021 to the American Academy of Arts and Sciences. In 2014 Moti Segev won the Israel Prize (highest honor in Israel) and in 2019 he has won the EMET Prize.
Above all his achievements, Moti takes pride in the success of his graduate students and postdocs, among them are currently 23 professors in the USA, Germany, Taiwan, Croatia, Italy, India, China and Israel, and many holding senior R&D positions in the industry.

Class of 2019 Fellow
Paul Bevilaqua is an aeronautical engineer who is well known for his work in aerodynamics and aircraft design. He worked for Lockheed Martin from 1985 to 2011, and is world-renowned for inventing the vertical lift concept in the F-35 Joint-Strike Fighter during his time there. He is a member of the National Academy of Engineering and a fellow of the American Institute of Aeronautics and Astronautics (AIAA). He is a recipient of several awards, including AIAA’s F. E. Newbold V/STOL and Aircraft Design awards and Daniel Guggenheim Medal; Lockheed Martin’s Kelly Johnson Inventors, Aerostar, and NOVA award; the Society of Automotive Engineering’s Aerospace Vehicle Design and Development Award; and the American Helicopter Society’s Paul E. Haueter Award. He was recognized as Engineer of the Year by Design News magazine in 2004.
Dr. Bevilaqua will work with faculty in the School of Aeronautics and Astronautics and the School of Mechanical Engineering. Potential topics of collaboration include aerodynamics, flow control, aeroacoustics, and new concepts in aircraft design.

Class of 2019 Fellow
Dr. Dara Entekhabi is a Neil Armstrong Distinguished Visiting Fellow member at Purdue Engineering. An expert in hydrological remote sensing, he is currently the science team leader for the NASA Soil Moisture Active Passive (SMAP). Dr. Entekhabi is the Bacardi and Stockholm Water Foundation Professor in the Department of Civil and Environmental Engineering and Professor in the Department of Earth, Atmospheric and Planetary Sciences at the Massachusetts Institute of Technology. He works in the areas of hydrology, hydroclimatology, and remote sensing. An expert in hydrological remote sensing, he is currently the science team leader for the NASA Soil Moisture Active Passive (SMAP) Mission. He is a member of the National Academy of Engineering, and a Fellow in the Institute of Electrical and Electronics Engineers, American Geophysical Union, and the American Meteorological Society.
Potential exists for Dr. Entekhabi’s collaboration with multiple groups across the colleges of Engineering and Science. Research topics will focus on new remote sensing techniques for soil and water, in particular the use of “signals of opportunity” in P-band (below 400 MHz), as well as broader applications of data from SMAP. This work is expected to impact the next generation of Earth remote sensing mission concepts, and the broader hydrology and agriculture communities.

Class of 2019 Fellow
Enrique Iglesia is the Theodore Vermeulen Professor in Chemical Engineering at the University of California at Berkeley. His research addresses the design, synthesis, and structural and mechanistic characterization of inorganic solids useful as catalysts for chemical reactions important in the production, conversion and use of energy carriers, in sustainable petrochemical syntheses, and in the protection of the environment. He is a member of the National Academy of Engineering, the American Academy of Arts and Sciences and the National Academy of Inventors. He has received several awards for his contributions to chemistry and chemical engineering. Most recently, he received the 2019 Michel Boudart Award for Advancement in Catalysis and the American Institute of Chemical Engineers’ William H. Walker Award for Excellence in Contributions to Chemical Engineering Literature.
Dr. Iglesia will work with faculty and students involved with the Center for Innovative and Strategic Transformation of Alkane Resources (CISTAR). He will engage CISTAR in research, industry innovation, entrepreneurship, and educational activities.

Class of 2019 Fellow
Dr. Randall Poston is Sr. Principal at Pivot Engineers, a structural engineering consulting firm in Austin, TX. An internationally recognized expert in structural engineering and member to the National Academy of Engineering, Randall Poston has established himself as one of the preeminent structural consultants in the United States. Dr. Poston has authored and delivered hundreds of papers and presentations related to the structural engineering industry, championed the repair of existing structures for upwards of 30 years, and dedicated his career to advancing the state of structural engineering knowledge. As past Chair of the American Concrete Institute (ACI) Committee 318 Structural Building Code (2008-2014), he oversaw a monumental effort to completely reorganize the concrete code, the first undertaking of its kind in the history of ACI. Engineering News-Record (ENR) named him a “Top 25 Newsmaker” of 2014 for his code reorganization leadership and ACI bestowed him with the Henry L. Kennedy Award for this work. Dr. Poston became the 96th President of the American Concrete Institute at the conclusion of the ACI Convention in Quebec City on March 28, 2019.
Dr. Poston will work alongside faculty in the Lyles School of Civil Engineering in research focused on structural engineering. At the recently held Spring 2019 Convention of the American Concrete Institute (ACI) in Quebec City, Dr. Poston gave his acceptance speech as the next President of ACI.

Class of 2019 Fellow
Andrea Rinaldo is the Professor of Hydrology and Water Resources and the Director of the Laboratory of Ecohydrology at Ecole Polytechnique Federale de Lausanne, Switzerland, as well Professor of Civil and Environmental Engineering at the University of Padova, Italy. He received his PhD (1983) in civil engineering at Purdue University. He is world-renowned as an authority and co-founder of the field of Ecohydrology and for his theory of self-organized fractal river networks and efficient transport networks. He is a member of the US National Academy of Engineering, the US National Academy of Science, and the Royal Swedish Academy of Sciences, and the recipient of the Horton Award from the American Geophysical Union, and the Dalton Medal from the European Geoscience Unions.
Lecture — February 24, 2022
Photonic Time-Crystals (continued)
Lecture — February 24, 2022
Lecture — August 24, 2021
Designing Aircraft for Best Value
Lecture — November 9, 2021
Q&A — Designing Aircraft for Best Value
QWould you recommend a non-US citizen to go into aerospace engineering because of the ITAR regulations?
AEvery aerospace product is not subject to ITAR restrictions. Most countries that buy American aircraft negotiate R&D and manufacturing “offsets” to reduce or earn back some of the cost of the airplane. In fact, an aerospace engineer with connections to a foreign buyer may have some advantages as an employee.
QWith your work on the F-35’s liftfan, what are your thoughts on similar technologies like the lift fans used in the Yak-141?
AThe YAK-141 used lift engines instead of a lift fan. An engine is more complicated and requires more maintenance than a lift fan. The hot exhaust gases impinge on the bottom of the aircraft as it takes off and lands; the undersides of all of YAK’s STOVL aircraft were coated with material similar to Space Shuttle tiles to insulate the airframe from the heat. The hot exhaust gases can also be ingested by the lift and cruise engines, causing the engines to stall. The Marine Corps told me not to even consider lift engines. McDonnel Douglas proposed a lift engine and were eliminated from the competition.
QRegarding your cost analysis, does the manufacturing cost induce the hardware and software testing cost as well or it is just the manufacturing cost of the final product?
AThe RAND equations were developed in 1985 and used data from the 1960’s and 1970’s. Avionics was a higher order term then, that I didn’t show. So the software was included, but it was almost a negligible term. Today, it is a significant cost item.
QHow do you think this discussion applies to an airplane that requires an entirely new propulsion system like H2 or Electric or Hybrid, etc?
AIn 1985, composite materials were not in the database, so we applied factors to the aluminum materials; they turned out to be optimistic. The engine suppliers will provide estimates for their new propulsion system concepts, just as the engine suppliers do today.
QHow profitable is U2?
AWe have not manufactured any new U-2’s in decades. I don’t know what profit was negotiated at the time. They were needed in a hurry and the prototypes were designed and built in 9 months. They are actually F-104’s with sailplane wings, having many parts in common. I imagine each aircraft was profitable, but there weren’t very many built.
QWhat design strategy/methods have you found the best to drive these cost considerations? SCUM. Agile, etc?
ALean principles applied to the design process: only include what the customer values, don’t add any gold plating, which includes using off-the-shelf parts when they are good enough.
QHow can we deal with a proposal that loses because it meets fewer requirement at a lower cost to a more capable more expensive proposal that gets cancelled due to cost later?
AToday, we work with our customer to tell him what everything he is considering will cost. When he ultimately issues a set of requirements, you have to meet all of them at the lowest cost. If a proposal is more capable than asked for in the requirements (gold plated) and more expensive, it can’t win, by law. Government contract administrators are instructed, “If you didn’t ask for it, you can’t pay for it.” On the JSF program, Boeing’s design couldn’t perform Mission X: a short take off, supersonic flight, and a vertical landing. They didn’t meet this basic requirement, so they lost.
AAE400 Senior Seminar Class Lecture
Seminar — March 22, 2019




AAE 451
Course — Spring 2021




J. William Uhrig and Anastasia Vournas Distinguished Short Course Series
Short Course Series (3 Videos) — March 26-28, 2019
Neil Armstrong Distinguished Visiting Fellow Bevilaqua maximizes visit
News — April 2019

As part of the inaugural Neil Armstrong Distinguished Visiting Fellow program, AAE alumnus Paul Bevilaqua gave a three-day short course, “Introduction to V/STOL Theory and Practice,” participated in the Industrial Advisory Council’s ethics panel, and met with faculty and students.
Bevilaqua (MSAAE ’68, PhD AAE ’73) spent about two weeks on campus from late March into early April.
“It was a good experience. I enjoyed it,” Bevilaqua says. “I’m a Purdue graduate, and I feel like I ought to be giving back.”
The Neil Armstrong Distinguished Visiting Fellows (NADVF) program brings highly accomplished and recognized scholars and practitioners to the College of Engineering to catalyze collaborations with faculty and students. Fellows are individuals who have been eminently recognized for their impact and achievements in engineering or related disciplines and who collaborate with Purdue Engineering faculty members on research projects and initiatives, including new research directions, industry engagement and on-campus and online educational efforts. Their selections were based on nominations made by faculty and the proposed impact of their research and visit on Purdue Engineering.

“My hopes are to make Purdue better known, to advertise its strengths. There seems to be too much Midwestern modesty along the lines of, ‘Shucks, ma’am, just doing my job,’ ” Bevilaqua says of his involvement in NAVDF. “I also want to help the younger professors get started and help some of the more experienced professors to try something different that will really make an impact so that people will say, ‘Wow, Purdue did that.’ ”
Bevilaqua’s short course gave an overview on Vertical and/or Short Take-Off and Landing (V/STOL) aircraft technologies, design, and performance. He also discussed fundamental concepts and technologies in V/STOL aircraft design.
Bevilaqua, now retired, spent much of his career developing V/STOL aircraft and made key theoretical contributions as well as practical innovations in V/STOL aircraft design. He joined Lockheed Martin as Chief Aeronautical Scientist and became Chief Engineer of the Skunk Works, where he played a leading role in creating the Joint Strike Fighter. He invented the dual cycle propulsion system that made a supersonic V/STOL aircraft practical and suggested that conventional and naval variants of this aircraft could be developed to create a common, affordable aircraft for all three services. He subsequently led the engineering team that demonstrated the feasibility of building this aircraft.
While on campus, Bevilaqua also met with Purdue’s AIAA chapter and spoke to AAE400, Senior Seminar, and AAE 551, Systems Engineering, classes.
“The students seemed to appreciate my talk. They asked some good questions, so they’re thinking,” he says. “Some of them just came up and said, ‘Thank you, I enjoyed it.’ That was nice.”

Lecture — October 10, 2019
Course — Fall 2019
Special Project Course!
AAE590: Earth Observation Mission Design
- Prof. Jim Garrison (AAE)
- Prof. Dara Entekhabi (MIT, Dept. of Civil and Environmental Engineering, NAE, NADVF)
This course is intended to provide students in engineering and science with the opportunity to develop a complete Earth observation satellite mission design, starting with the formulation of a compelling scientific hypothesis or applications concept, through selection of measurements and orbital coverage to meet defined science requirements, and concluding with a systems-level design for the satellite platform, instruments, and mission. The project will be structured around the NASA Earth Ventures mission competition, with the final product being presented in the form of a proposal for that competition.
This will be a 2-course sequence and students are encouraged to take both parts. Enrollment will be limited to 12 students total with a balanced participation between engineering students (AAE, ECE) and science/applications students (Civil, Agronomy, EAPS). Part II will be taught in parallel with a section of AAE450 Spacecraft Design.
Part I (Fall 2019)
- Review of the current state-of-the art in Earth remote sensing missions, and US as well as international policy, in particular, the 2017 NASA Earth sciences decadal survey.
- Identify a compelling science hypothesis or applications area, broadly within Earth science, and utilizing Purdue-developed instrument technology.
- Define mission orbit, constellation parameters and instruments.
- Conduct Observation System Simulation Experiment (OSSE) - evaluate sensitivity to different mission configurations.
- Define top-level science requirements.
Part II (AAE590, Spring 2020)
- Develop simulator for instrument measurement physics.
- Define instrument and mission requirements.
- Integrate an End-to-End mission simulator and use it to validate technical requirements.
- Write mission proposal to future NASA Earth Ventures solicitation.
- Parallel section of AAE450 Spacecraft Design course: Complete satellite and mission design, including launch vehicle selection, attitude dynamics and control system (ADCS), tracking, telemetry and command (TT&C), thermal and power analysis. Perform systems engineering for project. develop cost estimate and risk assessment.
Failure of Long-span Cable-Supported Timber Pedestrian Bridges — Lecture — October 20, 2020
Wind damage of solar power arrays and required repairs
Seminar — October 5, 2021
The Business of Civil Engineering
Seminar — March 4, 2020
Evaluation and Repair of Concrete Buildings: The Tale of Two High-Profile Projects in the US
Seminar — March 3, 2020
One Collapse, Two Load Tests, and Several Repairs
Seminar — April 9, 2020
Pivot Receives The Excellence in Concrete Construction Award
News

The Austonian slab edge repair project was previously awarded the International Concrete Repair Institute’s 2020 Project of the Year Award.
Pivot Engineers is pleased to announce that our engineers have been awarded the Excellence in Concrete Construction in Repair and Restoration award from the American Concrete Institute for our work on The Austonian slab edge repairs.
The Excellence in Concrete Construction Awards honors exceptional concrete construction from around the world. Projects are recognized for the degree of innovation, complexity, achievement, and value that concrete as a material provided. The American Concrete Institute’s awards are given by an independent panel of industry professionals.
Pivot was engaged to determine the cause of the premature damage to the 59-story Austonian building six years after its construction. Our engineers used non-destructive and destructive testing techniques to evaluate the structure. Our investigation determined that the cause of the concrete damage was carbonation-induced corrosion due to improper placement of slab reinforcement. The investigation also revealed that the issue was systemic and widespread.
Based on the investigation findings, Pivot developed a repair plan that included fulldepth removal and replacement of all exposed slab edges in the building (approximately 9,200 linear feet). Pivot’s repair design incorporated the use of glass fiber reinforced polymer (GFRP) reinforcement to address numerous dimensional constraints and prevent formation of future corrosion cells.
Pivot and the repair contractor coordinated the construction details and methods through off-site and on-site mockups, which allowed for extensive, yet swift, assessment and repair.
Pivot Engineers and the project team were formally presented with this award on October 18, 2021 during ACI’s Fall Convention.
Please join us in congratulating the project team for their award-winning work on this complicated project.

About the Award-Winning Project
Less than six years after the construction of the 59-story building, a six-foot-long piece of concrete from a slab edge fell more than 200 feet onto the podium. A visual survey performed by the owner identified 31 additional locations where evidence of structural distress was observed along the exposed slab edges. The owners were concerned about their own safety, as well as the safety of people and property around the building.
The owners then engaged Pivot to identify the cause of the premature damage and develop repair solutions. Using a suite of non-destructive and destructive testing techniques, Pivot determined the cause of the premature damage and concluded that the issue is widespread and systemic.
2020 Project of the Year – The Austonian: Slab Edge Repairs
News — November/December 2020

The Austonian is a 59-story, 683 ft. (208m) tall high-rise condominium that was completed in 2010 and is located in downtown Austin, Texas.
The building is comprised of reinforced concrete structural elements and unbonded, post-tensioned (PT) concrete slabs. The majority of the slab edges in a typical floor are covered with aluminum cladding, while the remaining slab edges are exposed to the elements. The building has approximately 1.75 linear miles (2.8 km) of exposed slab edges distributed over the entire height of the structure.
Read more — Pages 12-16 of Concrete Repair Bulletin Vol. 33, No. 6