The materials used in the construction industry have long been limited primarily to wood, concrete, masonry, and steel. Recently, however, the use of advanced materials that provide high-performance alternatives to these materials, such as innovative polymer composites, have the potential to transform the construction of new buildings, producing novel shapes and forms, and resulting in more efficient and sustainable structures that require less maintenance and can withstand even the most challenging environmental conditions.
While some traditional construction materials, like concrete and wood, exhibit composite properties, they often have limited tensile strength, stiffness, or durability. Composite construction materials have been developed to provide more robust and adaptable alternatives to these conventional materials, or in order to lower costs. Common examples include plywood, fiberglass, and cross-laminated timber.
Advanced composites typically take two or more materials with considerably different physical or chemical properties and combine them to create a material with attributes intended to be superior to those of the individual components. Among the most widely used of these newly developed materials are fiber-reinforced polymer (FRP) matrix composites, which mainly consist of reinforcing fibers embedded in a polymer binder, or matrix. The reinforcing fiber can be made of glass, carbon, boron, aramid, or organic matter like wood; while the polymer matrix can be made of polyester, vinyl ester, modified acrylic, or epoxy resins. The fiber determines the composite’s mechanical properties, such as its stiffness and strength; while the matrix lends the composite its physical characteristics, including its resistance to environmental effects. Thus, in addition to being strong, lightweight, and corrosion resistant, FRP composites can be engineered to provide specific performance characteristics, and to conform to varying design requirements.
Since 2009, the International Code Council’s International Building Code (IBC) has explicitly permitted the use of FRP composites in both interior and exterior parts of building structures. FRP composites were first used in building construction in conjunction with traditional construction materials. For example, FRP reinforcing bars have been used in concrete construction in place of steel, and FRP sheets have been used to wrap masonry or concrete walls, columns, or chimneys to increase their strength properties and improve their seismic performance. In addition, FRP roof shingles and siding panels have been applied to wood-framed houses, and composite materials have been integrated into a wide range of window, door, fencing, railing, and decking products.
Increasingly, however, FRP composites are being used to construct larger components of buildings, including in the residential sector. For example, recent advances in FRP composites have made it possible to construct basement walls that are lighter, more durable, more insulating, and more resistant to fire and water seepage than their conventional concrete counterparts.
For example, the Epitome panelized wall system developed by Wisconsin-based Composite Panel Systems LLC is an all-in-one system combining a vertical wall structure, continuous insulation, a double top plate, integrated stud cavities, waterproofing, and a vapor barrier. The composite walls can be load bearing or non-load bearing, and allow for an airtight transition between the floor and the foundation. The panels are assembled in a factory, and can be delivered to the site in a single trip and installed within hours. Because the panels are just seven inches thick, a foundation built out of the panels generally offers more usable living space than a basement constructed with cast-in-place concrete walls, which, after being stud-framed and insulated, can be as thick as 12 inches.
Currently, the use of such advanced FRP composite structural elements may entail slightly higher upfront costs than conventional materials. However, if life cycle costs are considered or environmental, comfort, or safety concerns are paramount, using building systems that rely on advanced composites may become preferable to relying solely on traditional construction materials, especially as new advanced composite building products enter the market.