Design of wooden structures
Introduction
Laminated lumber (in English Glulam) is a type of structural wood product made up of layers of construction wood joined by durable, moisture-resistant structural adhesives.
Basics
A piece of laminated wood is obtained by grouping several sheets of wood in parallel. These structural elements are primarily used as vertical columns, horizontal beams, and arches. They can be easily manufactured with curved shapes and in a wide range of characteristics and appearances.[1] Connections are normally made with screws or steel plates.
Laminated wood optimizes the structural values of the wood. Due to its composition, large pieces of laminated wood can be made from several smaller trees grown in young forests and plantations.
Laminated lumber provides the strength and versatility of large pieces of lumber without relying on slow-growing, solid wood trees.[2].
Like other manufactured wood products, it reduces the overall amount of wood used compared to solid wood pieces, as it lessens the negative impact of knots and other small defects in each piece of wood.
Laminated wood has much lower energy content than reinforced concrete and steel, although it has a higher energy content than solid wood. Still, the laminate process allows wood to be used with greater spans, loads, and more complex shapes than reinforced concrete or steel. Laminated wood is one-tenth the weight of steel and one-sixth the weight of concrete; the energy content to produce it is one-sixth of an equivalent amount of steel in strength.[3] Laminated wood can be manufactured in a wide variety of shapes, offering architects artistic freedom without sacrificing structural requirements. The great resistance and rigidity of laminated wood beams and arches allow large spans to be covered without intermediate supports, facilitating greater flexibility in the design than other traditional methods of construction with wood. The measurement is limited only by the considerations of transportation and handling of the pieces.[4].
History
One of the earliest uses of laminated timber for roof structures is credited to King Edward VI College, a school on Bugle Street, Southampton, England, built in 1866, and designed by Josiah George Poole.[6] The building is now the Southampton Marriage Registry Office.[7].