Composite construction is a generic term to describe any building construction involving multiple dissimilar materials. Composite construction is often used in building

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

watercraft Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sai ...

, and

building construction Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and com ...

. There are several reasons to use

composite materials A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or ...

including increased strength,

aesthetics Aesthetics, or esthetics, is a branch of philosophy that deals with the nature of beauty and taste, as well as the philosophy of art (its own area of philosophy that comes out of aesthetics). It examines aesthetic values, often expressed t ...

, and environmental

sustainability Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...

Structural engineering

structural engineering Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and muscles' that create the form and shape of man-made structures. Structural engineers also must understand and cal ...

, composite construction exists when two different materials are bound together so strongly that they act together as a single unit from a

structural A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such ...

point of view. When this occurs, it is called composite action. One common example involves

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistan ...

beams supporting

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...

floor slabs. If the beam is not connected firmly to the slab, then the slab transfers all of its weight to the beam and the slab contributes nothing to the load carrying capability of the beam. However, if the slab is connected positively to the beam with studs, then a portion of the slab can be assumed to act compositely with the beam. In effect, this composite creates a larger and stronger beam than would be provided by the steel beam alone. The structural engineer may calculate a transformed section as one step in analyzing the load carry capability of the composite beam.

House building

flitch beam A flitch beam (or flitched beam) is a compound beam used in the construction of houses, decks, and other primarily wood-frame structures. Typically, the flitch beam is made up of a vertical steel plate sandwiched between two wood Wood is ...

is a simple form of composite construction sometimes used in North American

light frame construction Framing, in construction, is the fitting together of pieces to give a structure support and shape. Framing materials are usually wood, engineered wood, or structural steel. The alternative to framed construction is generally called ''mass wal ...

. This occurs when a steel plate is sandwiched between two wood joists and bolted together. A flitch beam can typically support heavier loads over a longer

span Span may refer to: Science, technology and engineering * Span (unit), the width of a human hand * Span (engineering), a section between two intermediate supports * Wingspan, the distance between the wingtips of a bird or aircraft * Sorbitan ester ...

than an all-wood beam of the same cross section.

Deck construction

Composite wood decking

The traditional decking material is pressure-treated wood. The current material many contractors choose to use is composite decking. This material is typically made from wood-plastic composite or Fiberglass Reinforced Plastic (FRP). Such materials do not warp, crack, or split and are as versatile as traditional pressure treated wood. Composite decking is made through several different processes, and there are a multitude of sizes, shapes, and strengths available. Depending on the type of composite selected the decking materials can be used for a number of other construction projects including fences and sheds.

Composite steel deck

In a composite steel deck, the dissimilar materials in question are steel and concrete. A composite steel deck combines the tensile strength of steel with the compressive strength of concrete to improve design efficiency and reduce the material necessary to cover a given area. Additionally, composite steel decks supported by composite steel joists can span greater distances between supporting elements and have reduced live load deflection in comparison to previous construction methods.

Cement-polymer composites

Cement-polymer composites are being developed and tested as a replacement for traditional cement. The traditional cement used as stucco rapidly deteriorates. The deterioration causes the material to easily crack due to thermo-processes becoming permeable to water and no longer structurally sound. The

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...

in conjunction with Materials and Electrochemical Research Corporation tested a cement-polymer composite material consisting of

crumb rubber Crumb rubber is recycled rubber produced from automotive and truck scrap tires. During the recycling process, steel and tire cord (fluff) are removed, leaving tire rubber with a granular consistency. Continued processing with a granulator or c ...

made from

recycled Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...

rubber tires A tire (American English) or tyre (British English) is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which t ...

and

cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. Cement mixe ...

. It was found that 20% crumb rubber can be added to the cement mixture without affecting the appearance of the cement. This new material was tested for strength and durability using American Society for Testing and Materials (

ASTM International ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, ...

) standards.

High-performance composites

A newer but growing sector in the composite construction sector is the high-performance decking that comes from companies like Trex Decking and Fiberon. High performance composite decking has emerged in recent years to combat earlier generations of composite decking like wood plastic composite (WPCs) that were struggling to maintain credibility in the marketplace. Research is showing now, however, that consumers are choosing composite decking products over wood 11 times to 1. Initial concerns regarding moisture intrusion in composite decks has led to the rise of high performance decking products with protective shells, often referred to as “

capped composite decking Composite lumber is a material that is a mixture of wood fiber, plastic, and some type of binding agent. These ingredients are put together to form a material that is denser, stronger, and heavier than wood alone, a wood-plastic composite. Histo ...

.” Capped composite decks have a high performance finish with the addition of the shell that is often called a “cap-stock.” This shell covers either all four sides of the composite board or just the top and sides, depending on the brand. Manufacturers apply the cap to the board using a process called ''co-extrusion''. Most capped composite decking comes with some kind of warranty against stains and fading.

References

{{Reflist Civil engineering Construction Building materials Prestressed concrete construction