CFRP is well-suited to repairs because buildings have varying degrees of stresses and strains in different areas, and composite materials can be customized as needed. “It’s not like using a steel plate or jacket, which is extremely heavy and prone to corrosion,” says David White, P.E., vice president of technical services at Sika. “With FRP, you can custom design the weight of the fabric and the orientation of the fibers so it’s truly an engineered solution.”
Nearly all of the 180,000-square-foot façade of the Harris County Administration Building was covered with CFRP, which was installed by Structural Concrete Systems LLC using scaffolds while the building was still occupied. “That’s where the FRP materials showed their true worth,” says White. “I couldn’t imagine trying to affix a steel plate on the outside of this building. The lightweight, non-corrosive nature and ease of installation made CFRP a perfect product for the situation.”
One of the most common uses of composites in architecture, crossing over both new construction and restorations, is ornamentation. EDON Corporation in Horsham, Pa., has supplied FRP architectural ornamentation since the early 1980s. It recently completed phase one of a cornice project for Penn Avenue Place in Pittsburgh. The three-piece cornice had to be done just right – and under a tight deadline – because hundreds of thousands of people would be gazing at it during the 2016 Christmas season.
The GFRP cornice runs along the sides of the building’s sixth story, meeting at the corner where Pittsburgh’s iconic Unity Tree is displayed each Christmas. The 100-foot artificial tree, which wraps around Penn Avenue Place, is decorated with 2,500 lights and 2,000 ornaments. The new cornice provided by EDON provides a beautiful backdrop.
When the original metal cornice on the 110-year-old building began deteriorating, netting was added to the building to protect pedestrians from potential falling debris. EDON was hired for the restoration. “It was a historic cornice and had to be reproduced to match the original,” says Matt Axel, president of EDON.
The contractor provided original pieces of the cornice to EDON, which sent them to its pattern maker in Boston. Once the fabricator received the patterns back, it created fiberglass molds and then manufactured the cornice sections using a spray-up process. The cornice pieces are made from OptiSpray™ chopped GFRP from Owens Corning and Hetron™ fire-resistant polyester resins from Ashland. The cornices, which are approximately 8 feet, 9 inches high and project more than 4 feet out from the building, include an upper acroteria band, a cornice with molded coffers and a lower cornice with molded brackets and decorative elements nicknamed “elephant toes.”