The markets: Construction (2017)

In 2009, the International Building Code’s new Subsection 12 approved the use of fiber-reinforced polymer (FRP) composites as alternatives for conventional materials used in commercial building envelopes. In 2016, composites advocates saw additional evidence that those alternatives could be realized cost-effectively.

In the still-developing building and construction segment, composites adoption picked up in 2015, spurred by some promising regulatory changes. Early successes in the residential fencing and decking segment were followed Laudable efforts by the American Composites Manufacturers Assn.  (ACMA, Arlington, Va.) to modify the International Building Code (IBC) and a growing awareness of composites’ environmental sustainability through lifecycle analysis tools had previously earned the composites industry only small gains in what architects call the “building envelope.” Exterior decorative elements, such as cornices and columns and window lineals, entry doors, skylights and light panels represented a beginning. But industry observers saw big opportunities for composites in wall panels, foundations, building cladding and roofing. In 2014, that door began to open, as architects responded to the International Code Council’s (ICC, Washington, D.C.) revised (2009) International Building Code, which now includes IBC Chapter 26, “Plastic,” and Subsection 12, “Fiber-Reinforced Polymer.” At CAMX 2015, in Dallas TX, US, Marcio Sandri, VP and Managing Director glass reinforcements for Owens Corning Composite Solutions Business (Toledo, OH, US) told attendess that the construction market would consume 1.45 million MT of glass-reinforced composites annually by 2018, 3.6% growth yearly.

Unitized panel systems will help spur the increase. A popular alternative to conventional, stick-built construction in building envelopes because they can be prefabricated, offsite, under controlled factory conditions, they vastly simplify onsite installation, decreasing expensive jobsite labor and shortening construction schedules. In 2009, the International Code Council’s (ICC, Washington, D.C.) International Building Code (IBC) approved the use of fiber-reinforced polymer (FRP) composites for such systems. In 2014, Kreysler & Associates Inc.’ (American Canyon, CA, US) Fireshield 285 panel system made them practical in structures taller than 12m with an FRP system that could pass the NFPA 285 fire-resistance certification, allowing it to be used on what is currently the largest FRP façade installation in the US: the San Francisco Museum of Modern Art (SFMOMA) expansion (see “Editor's Picks”).

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In 2016, the building codes’ “open door” to composites encouraged architectural creativity, and as a result, greater diversity. Composites found their way into applications as diverse as holiday displays and as effective thermal interrupters, as builders discover that replacing metal fasteners with composite fasteners could make a huge difference in thermal/environmental sustainability. From highs in the summer pushing 33°C to winter lows in the range of -40°C, the climate in the US state of Alaska presents a challenge for engineers and architects. A notable example was during design and construction of the Bassett Army Community Hospital at Fort Wainwright, a US Army base adjacent to the city of Fairbanks, just 190 km south of the Arctic Circle, where extreme temperature swings were a serious concern.

Architectural joint venture HKS Inc./Wingler & Sharp (Dallas, TX, US), which led the project, anticipated problems with thermal conductivity and thermal bridging, whereby building heat is lost through metal-to-metal contact between fasteners and components in exterior walls. When too much thermal transference occurs, cold spots develop and moisture condenses, which can lead to mold growth. Fiber-reinforced polymers (FRPs) have a thermal conductivity 1/100th that of steel and offer the potential for significant energy savings when employed as a thermal break between the exterior and interior of a building.

With that in mind, the project’s chief structural engineer, Larry A. Johnson, P.E., designed a structural solution that minimizes the thermal conductivity through the exterior walls. He bolted composite structure to the spandrel beams (beams that span between structural columns) of the project’s structural steel framing system. Strongwell’s (Bristol, VA, US) trademarked EXTREN pultruded fiberglass/polyester structural shapes were specified, including 300-mm by 12.5-mm flanges, 200-mm by 55-mm by 9-mm channels and FIBREBOLT FRP threaded composite rods and hex nuts to support the exterior masonry façade/cladding. The composites act as an effective thermal break between the warm and cold sides of the exterior walls.

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