Membrane structure, Structure with a thin, flexible surface (membrane) that carries loads primarily through tensile stresses. There are two main types: tent structures and pneumatic structures. The Denver International Airport (1995) features a terminal building roofed by a white membrane stretched from steel masts. Another such structure is London’s The O2 (formerly Millennium Dome), which has a tensioned membrane structure with…

Cable structure, Form of long-span structure that is subject to tension and uses suspension cables for support. Highly efficient, cable structures include the suspension bridge, the cable-stayed roof, and the bicycle-wheel roof. The graceful curve of the huge main cables of a suspension bridge is almost a catenary, the shape assumed by any string or cable suspended freely…

Girder, in building construction, a horizontal main supporting beam that carries a vertical concentrated load. girder Beam Beam, in engineering, originally a solid piece of timber, as a beam of a house, a plow, a loom, or a balance. In building construction, a beam is a horizontal member spanning an opening and carrying a load that may…

Framed building, structure in which weight is carried by a skeleton or framework, as opposed to being supported by walls. The essential factor in a framed building is the frame’s strength. Timber-framed or half-timbered houses were common in medieval Europe. In this type the frame is filled in with wattle and daub or brick. A modern lightweight wood-frame structure, the balloon-frame…

Post-and-lintel system, in building construction, a system in which two upright members, the posts, hold up a third member, the lintel, laid horizontally across their top surfaces. All structural openings have evolved from this system, which is seen in pure form only in colonnades and in framed structures, because the posts of doors, windows, ceilings, and…

Reinforced concrete, concrete in which steel is embedded in such a manner that the two materials act together in resisting forces. The reinforcing steel—rods, bars, or mesh—absorbs the tensile, shear, and sometimes the compressive stresses in a concrete structure. Plain concrete does not easily withstand tensile and shear stresses caused by wind, earthquakes, vibrations, and other forces and is…

Arch, in architecture and civil engineering, a curved member that is used to span an opening and to support loads from above. The arch formed the basis for the evolution of the vault. Arch construction depends essentially on the wedge. If a series of wedge-shaped blocks—i.e., ones in which the upper edge is wider than the lower…

Wall, structural element used to divide or enclose, and, in building construction, to form the periphery of a room or a building. In traditional masonry construction, walls supported the weight of floors and roofs, but modern steel and reinforced concrete frames, as well as heavy timber and other skeletal structures, require exterior walls only for shelter and sometimes dispense with them on the…

Masonry, the art and craft of building and fabricating in stone, clay, brick, or concrete block. Construction of poured concrete, reinforced or unreinforced, is often also considered masonry. masonry The art of masonry originated when early man sought to supplement his valuable but rare natural caves with artificial caves made from piles of stone. Circular stone huts, partially dug…

Bearing wall, orload-bearing wall, Wall that carries the load of floors and roof above in addition to its own weight. The traditional masonry bearing wall is thickened in proportion to the forces it has to resist: its own weight, the dead load of floors and roof, the live load of people, as well as the lateral forces of arches, vaults, and wind. Such…