Considered by many to be the gateway to the Caribbean, the Luis Muñoz Marin International Airport in Carolina, Puerto Rico is the region's busiest airport, transporting more than 10.6 million passengers a year to and from the island paradise. In the early 2000s, with the number of travelers at an all-time high and still growing, the Puerto Rico Ports Authority launched an ambitious plan to upgrade the facility with new runways, pavement and apron expansions, new lights systems and a new passenger terminal with enhanced amenities. The first phase of the construction began in 2006, with the new 285,000 sq. ft. Terminal A taking center stage. The $400 million project is expected to be completed in 2009.

The Puerto Rico Ports Authority commissioned architect Manuel Goicoechea-Castedo and his firm, MGA Consultants Inc., of Isla Verde, PR, to design a striking new terminal to accommodate the growing group passenger traffic associated with the cruise ship industry, and handle the influx of guests attending events at the new Convention Center and Sports Coliseum in Hato Rey. And as the new terminal would be the first building encountered as one approaches the terminals, they wanted the building to be architecturally distinctive, giving passengers a unique experience associated with their first visit to Puerto Rico.

Goicoechea-Castedo responded with a landmark structure that features canted glass walls rising to support a massive radiused canopy that extends outward some 83'. The canopy is skinned with Reynobond® ACM (aluminum composite material) as is an adjoining light-filled concourse.

Primarily due to its sleek metal canopy, the terminal's appearance has been compared to that of a flying saucer. But the architect said it was the constraints of the site rather than outer space that influenced the project's design. "We had a formidable challenge accommodating the required functions within the limited three dimensional envelope imposed by the required clearances from runway 10/28 and vehicular circulation on the north," said Goicoechea-Castedo. "We selected Reynobond® ACM for the project primarily for its clean, durable and relative maintenance-free characteristics. That it has contributed much of the flair and high-tech aesthetics to the architecture of the building is the gravy."

From the beginning, Goicoechea-Castedo worked closely with Dave Clapperton, a principal of The Miller-Clapperton Partnership Inc. of Austell, GA, and Gerardo Fernandez, a principal of Bosenson Inc., of Guaynabo, PR, to specify and vet the materials for the project. On the recommendation of both specialists, Reynobond® ACM was one of the approved products specified for the application. As the design for the project progressed, Clapperton and Fernandez worked with a team of specialists to engineer additional structural framework and the Reynobond® ACM panels for the project. The companies have collaborated before on projects including the Amgen Administration Office Building in Juncos, PR; Universal Insurance in Mayagüez, PR; and the Banco Popular Commercial Center in Hato Rey, PR. Miller Clapperton was also part of the Puerto Rico Convention Center in San Juan and the Coliseo de Puerto Rico in Hato Rey. The firms' extensive knowledge of the island's building codes and structural challenges provided essential support for the success of the project. Charles Waler PE, Inc. of Ft. Lauderdale, FL was the Structural Engineer of Record for the project.

Miller Clapperton engineered and fabricated 42,588 sq. ft. of Reynobond® ACM, 4 mm, PE core in Pure White with a Colorweld® 300 finish for the project. The panels were shipped to San Juan by boat from Savannah, GA over the course of a year. Bosenson installed the panels, and for areas where adequate as-built information was not readily available, Bosenson completed the fabrication process in the field. To prepare for that task, the company sent its field foreman and key mechanics to Miller Clapperton's facility in Austell, GA for several days of fabrication training prior to the installation. QB Construction of San Juan, PR served as the general contractor for the project.

"The most challenging element of this project was the HUBB Roof structure which when viewed in its final form really does look like a large tilted Flying Saucer," said Clapperton. "It is approximately 255' wide by 235' deep and has a panel surface designed to a 341' radius. To add to the geometry challenge, the bottom or belly of this saucer gradually transitions from concave to convex moving from the front to the back of the arrival hall. Looking down on this saucer or dish from above in the plan, the back outside radial edge facing the airside was cut off, creating a straight edge along the back of the dish. This edge occurs along the soffit/ceiling condition, which is convex and is the low point of the tilted saucer. To accommodate this change in concavity, the perimeter bullnose had to make a complicated transition at the southwest and southeast corners, while maintaining the consistency of the intended roof site line." Engineering and framing for the transition of the roof from concave to convex was accomplished by using a series of 14- and 16-gauge cold rolled galvanized studs in both 6" and 8" sizes.

To further complicate matters, cast-in-place concrete stair structures interrupted the corner transitions, but required that the panel joints and sightlines be maintained from the interior ceilings to the exterior soffits and bullnose roof edge panels. The entire perimeter of the soffit panels where they transition to the 14" radius bullnose Reynobond® ACM panel edge has a continuous 4" reveal. "When viewing the interior ceiling from within the arrival hall," said Fernandez, "the overall structure looks like the underneath side of a saddle with the back (airside) surface curving up and away from the viewer. The curvature and surfaces are very gradual so as not to present the appearance of abrupt change. The intersection between the curtainwall and Reynobond® ACM ceiling/soffit is clean and uninterrupted, which creates a continuity of flow of the surfaces from the interior to the exterior. The high point of the HUBB roof faces north and presents itself to the arriving passengers on the landside creating a rather dramatic structure." The interior ceilings transition through the curtainwall lines to create an exterior soffit which is approximately 12-feet deep on the East and West and forms an 83-foot wide canopy structure on the North, which protects arriving passengers from the elements. The transition from the interior perforated metal ceiling to the Reynobond® ACM through the curtainwall was accomplished by using Reynobond® ACM panels in lieu of fixed-form aluminum panels due to time constraints.

In addition, a number of structural framing requirements were not adequately detailed on the contract drawings. Bosenson and Miller Clapperton not only brought them to the attention of the architect and general contractor, but also offered cost effective solutions to the problems. "There were elements of the design where our Reynobond® ACM panel system had to terminate and little consideration was given to how that might be accomplished," continued Clapperton. "To a large degree, the resolution of this condition fell on Bosenson and they were able to modify panel framing and attachments to stay within the recommended design guidelines provided by Miller Clapperton and structural engineers, BLB Consulting, Inc. of Mableton, GA, for structural dequacy and provide the architect with pleasing and design-consistent surfaces."

3-D modeling was used to engineer the tilted 'Flying Saucer' surface interface with the tapered curtainwall supports, then transitioning back to the structural steel roof framing truss system with an efficient light gauge framing system that could be adaptable from light interior loads to exterior hurricane-force wind loads without creating complex connections and superfluous support elements. Bosenson brought in a local surveyor to shoot thousands of points that were input into AutoCAD® by Progress Engineering, LLC of Union, Missouri to create a utilitarian, multi-functional 3-D model complete with joints, XYZ coordinate system, which enabled Miller Clapperton and Bosenson to calculate the panel surface distance from specific work points on the steel super structure, and enhanced the engineering of the light gauge framing system and Reynobond® ACM panels.

To further strengthen the panel structure, Miller Clapperton designed a new stiffener system for the project to efficiently resist the hurricane wind forces and deflection criteria for relatively large panels applied in a soffit condition. Miller Clapperton also supplied and Bosenson installed a louvered mechanical screen wall complete with intermediate support framing on the transitional area of the roof that runs between the HUBB and Concourse. The screen wall, designed by Dave Clapperton to cover the A/C cooling towers, and supplied by Construction Specialties of Cranston, NJ, had extended 'dog legs' which ran down to an entry roof canopy on the landside and all the way to the tarmac on the airside. The finish surface of the louver screen had to be designed to align these three different areas of the structure.